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Summary: Fresh‐cut apples are susceptible to enzymatic browning and spoilage. The objective of this study was to evaluate the effect of different coatings on fresh‐cut apples and develop a predictive model for their shelf life. The apples were treated with antioxidant peptide from Candida utilis (CUH), carboxymethyl chitosan (CMCS), and composite coatings, and their physicochemical properties were subsequently evaluated. Key factors identified through correlation analysis of shelf life were used as input parameters for a partial least squares regression (PLSR) model to predict the shelf life of fresh‐cut apples treated with different coatings. The results indicate that CUH, CMCS, and CUH‐CMCS coatings effectively delay the deterioration of fresh‐cut apples. Notably, the CUH‐CMCS composite coating demonstrated superior performance, showing only a slight 3.50% increase in the browning index (BI) during storage. Minimal changes were observed in weight loss and firmness, while overall total acidity (TA) and pH exhibited slight decreases. Moreover, the levels of ascorbic acid (Vc), polyphenol oxidase (PPO), and peroxidase (POD) were significantly lower compared to the control group, and the total bacterial count increased by no more than 0.7 log CFU g−1. The PLSR model accurately predicted the shelf life of fresh‐cut apples treated with different coatings, with Rc2 and Rp2 values both exceeding 0.90. The research results indicate that the coating and model developed in this study offer a novel approach for preserving and managing fresh‐cut apples. [ABSTRACT FROM AUTHOR]

Young coconuts (Cocos nucifera L.) used for export are trimmed to reduce their size and weight to lower transport costs. However, trimmed coconuts have a shorter shelf life due to microbial spoilage and surface discoloration caused by enzymatic browning. To minimize these effects, trimmed coconuts were dipped in an anti-browning agent, sodium metabisulfite (SMB), and stored under ambient conditions. However, there have been no reports on the effects of SMB treatment on metabolome changes in the flesh and water of young coconuts. Hence, this study investigated the metabolite changes in trimmed young coconuts after SMB treatment under different storage conditions using a gas chromatography (GC)/mass spectrometry (MS) metabolomic profiling approach. Tall young coconut samples were trimmed and treated with a 2% SMB solution for 5 min before storage at 25 °C or 4 °C for 2–4 weeks. Coconut flesh and water samples were collected after storage for 0, 2, and 4 weeks, and were subjected to GC–MS analysis. The results showed that the major metabolites affected by coconut deterioration were amino acids, sugars, and sugar alcohols. SMB treatment and/or refrigeration can help prevent metabolite changes in the flesh and water of young coconuts. In the future, improvements in storage conditions based on metabolite profiles should be explored. [Display omitted] [ABSTRACT FROM AUTHOR]

Browning reactions caused by oxidative stress occurring during postharvest procedures significantly compromise the quality of ready‐to‐eat (RTE) vegetables, negatively affecting their market value. Polyphenol oxidase (PPO) and peroxidase (POD) are two major enzymes involved in this phenomenon, as they oxidize phenolic compounds to quinones, which in turn polymerize to brown pigments. Recently, there has been an increasing interest in developing antibrowning treatments using food by‐products. Herein, the efficiency of a kiwi peel extract in reducing enzymatic browning of minimally processed lettuce (Lactuca sativa) has been investigated. PPO and POD activities showed an opposite spatial distribution within the leaf, with a higher POD activity in the midvein (MV) and in the inner lamina tissues, and a prevalence of PPO activity in the mesophyll. Considering that MV lignified tissues are those mainly affected by browning, the temporal trend of POD activity over a 20‐day storage period at 4°C was investigated. Data showed that treatment with a kiwi peel extract hinders both the increasing trend of POD activity and browning development compared to control leaves. These results could be potentially useful for the industry as they confirm that natural extracts, such as kiwi peel extract, can be valuable for extending the shelf‐life of RTE products. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aims to investigate the potential mechanism of melatonin (MT) to alleviate the browning of postharvest lotus seeds. 1) The samples were treated with the distilled water, nitric oxide (NO), MT, the inhibitor of nitric oxide synthase (NOS) nomega-nitro-L-arginine methyl ester (L-NAME), the inhibitor of nitrate reductase (NR) tungstate (TUN), and the scavenger of NO carboxy-PTIO (cPTIO), MT + L-NAME, MT + TUN and MT + cPTIO. A systematic analysis was implemented to explore the possible pathway of NO biosynthesis in the lotus seeds. Then, the levels of key enzymes and substances were determined to involve in the NO biosynthesis. The results showed that the endogenous NO content of the MT treated lotus seeds was significantly higher than that of the control. The NOS activity of lotus seeds treated with MT was promoted by 60.36%−71.08% before 3 days of storage. In addition, the MT treatment significantly increased the contents of Larginine and citrulline (P <0.05), which were the key substances in the NO biosynthesis. It was notable that the citrulline content in the MT treated sample was 1.44~1.59 times than those of the controls. By contrast, there was the varying influence of MT treatment on the activity of NR in lotus seeds. There was the beneficial effect of MT on the lotus seeds and the endogenous NO content of the tissue, when the MT was combined with the inhibitor of NR (TUN). However, this beneficial effect disappeared, when the MT was combined with the inhibitor of NOS (L-NAME) for treating the lotus seeds. The endogenous NO content in this treatment was significantly lower than that in the control. Therefore, the exogenous MT treatment was induced the NO biosynthesis in lotus seeds through the pathway of NOS. 2) The potential mechanism of MT was clarified to regulate the browning of lotus seeds. The phenolic compounds were identified in the lotus seeds using a LC20 HPLC (Shimadzu, Japan) system coupled to a TripleTOF® 5600 + quadrupole time-of-flight (QTOF) mass spectrometer equipped with a DuoSpray™ ion source (Sciex, Ontario, Canada). It was found that there were six flavanols and seven phenolic acids in the lotus seeds, and the content of catechin, a type of flavanol, accounts for over 60% of the total phenol content, the following was ellagitannin, a type of phenolic acid, accounts for 7.45% of the total phenol content. It infers that the catechin was the major phenolic compound of lotus seeds. The flavan-3-ol was the most common direct natural substrate of polyphenol oxidase (PPO) in the plant, especially for the catechin and epicatechin. Thereby, the potential mechanism of MT was determined, where the catechin metabolism was regulated to induce the NO production in the following experiments. The results indicated that the activity of PPO in the MT treated lotus seeds was lower by 35.39%−57.36% than those in the control. What’s more, the MT treatment significantly increased the activities of key enzymes, including cinnamate-4-hydroxylase, dihydroflavonol reductase, chalcone synthase, chalcone isomerase and colorless anthocyanin reductase (P <0.05) in the catechin synthetic metabolism. As a result, the content of catechin in the MT treated sample was higher by 15.35%−47.86% than those in the control after 1 days of storage. Whereas, this positive effect was negated, when the MT was combined with LNAME or cPTIO for treating lotus seeds. Therefore, it was concluded that the exogenous MT treatment was induced the biosynthesis of NO through NOS pathway, and then the accumulated NO acted on the catechin metabolism of lotus seeds. The MT treatment was used to inhibit the PPO activity, and then the catechin was suppressed to participate in the enzymatic browning; The biosynthesis of catechin was promoted in this treatment. Consequently, the lotus seeds browning was also alleviated by the MT treatment. These findings can provide the theoretical and technical support to preservation of lotus seeds and the signal transduction between MT and NO. [ABSTRACT FROM AUTHOR]

This manuscript focuses on the development of Fruit Storage Chamber (FSC) equipped with nano-TiO2 and its modular prototype to improve the value of bamboo-based FSC by its photocatalytic and feasibility aspects. Its effects on fruit shelf life and ripening-related gene expression were studied. Cavendish bananas were stored in FSC equipped with nano-TiO2 and modular FSC for treatments. Relative expression level of ethylene biosynthesis-related (MaACS1, MaACO1) and polyphenol oxidase (MaPPO4, MaPPO5) genes were examined. The dynamics of ripening variables throughout the storage period were illustrated in regression lines, followed with hypothesis testing. Banana quantity showed no significant changes upon storage in FSC equipped with nano-TiO2. Physical appearance indicated a ripening delay of up to two days on nano-TiO2 treatments compared to control. Ethylene production rate and ethylene related gene expression were not significantly altered. Browning index was more maintained in nano-TiO2 treated samples, supported by the observation of slower increase of MaPPO4 and MaPPO5 relative expressions compared to control. The findings highlight the suppression of fruit ripening related gene expression and the maintenance of fruit quality in treated samples compared to control, indicating the potential use of nano-TiO2 to prolong banana shelf life. [ABSTRACT FROM AUTHOR]

Different solvents water, ethanol and ethanol/water (6:4 v/v), were compared in the extraction of pomegranate peels and seeds (PPS) in terms of recovery yields, antioxidant properties, and antimicrobial action against typical spoilage bacterial and fungal species. The best performing extract (ethanol/water (6:4 v/v) was shown to contain mostly ellagic acid and punicalagin as phenolic compounds (5% overall) and hydrolysable tannins (16% as ellagic acid equivalents) and was able to inhibit the growth of the acidophilic Alicyclobacillus acidoterrestris at a concentration as low as 1%. The preservation of the organoleptic profile of A. acidoterrestris-inoculated apple juice with extract at 1% over 20 days was also observed thanks to the complete inhibition of bacterial growth, while the extract at 0.1% warranted a significant (40%) inhibition of the enzymatic browning of apple smoothies over the first 30 min. When incorporated in whey proteins' isolate (WPI) at 5% w/w, the hydroalcoholic extract conferred well appreciable antioxidant properties to the resulting coating-forming hydrogel, comparable to those expected for the pure extract considering the amount present. The WPI coatings loaded with the hydroalcoholic extract at 5% were able to delay the browning of cut fruit by ca. 33% against a 22% inhibition observed with the sole WPI. In addition, the functionalized coating showed an inhibition of lipid peroxidation of Gouda cheese 2-fold higher with respect to that observed with WPI alone. These results open good perspectives toward sustainable food preservation strategies, highlighting the potential of PPS extract for the implementation of WPI-based active packaging. [ABSTRACT FROM AUTHOR]

Polyphenol oxidase (PPO) is the key enzyme responsible for enzymatic browning. To extend the shelf life of shredded lettuce, knowledge about biochemical PPO properties is required. The characterization of the enzyme from shredded, cold-stored lettuce was performed using pyrocatechol and the endogenous substrate (ES) (lettuce phenolics). The optimum pH and temperature for PPO activity were 5 and 50 °C, respectively. Natural infusions used as the PPO inhibitors (IC50) were ranked as follows: lovage (0.09%), marjoram (0.13%), orange peel (0.14%), oregano (0.15%), basil (0.22%), lemon peel (0.24%), parsley leaves (0.58%), and wheat bran (1.06%). Among well-recognized PPO inhibitors, kojic acid (0.00043%), ascorbic acid (0.00053%), and L-cysteine (0.00085%) were the most effective. Among the metal ions, MgCl2, FeCl2, and CaCl2 at 0.5 mM inhibited the PPO activity most effectively (by 28%, 27%, and 21%, respectively). The substrate used (pyrocatechol/ES) significantly influenced the enzyme inhibition. Using pyrocatechol, the lovage extract acted in a mixed mode (Kmi = 27.8 mM, Vmaxi = 2.03 mU), while the ES acted according to the non-competitive mode (Kmi= 0.57 mg GAE/mL, Vmax = 0.0046 U). The study confirms that natural extracts are more effective than L-cysteine when the ES is used. A pre-storage treatment with an infusion may be potentially used to improve the quality of shredded lettuce. [ABSTRACT FROM AUTHOR]

Carica papaya is high susceptibility to microbial degradation and enzymatic browning due to its high moisture content, significantly limiting its post-harvest shelf life and marketability. While various drying techniques have been explored to overcome these issues, there is a lack of comprehensive studies that establish the ideal parameters for superheated steam drying (SSD) to maximise the retention of bioactive compounds while enhancing the functional properties of papaya powder. This study aims to investigate the impact of superheated steam drying (SSD) time and temperature on the physiochemical attributes, functional properties, and antioxidant capacity of papaya powder. Papaya powders obtained from drying at different temperatures (100, 110 and 120 °C) and times (120 and 140 min) have been analysed for yield, colour, moisture content, water activity, functional characteristics, and antioxidant capacity. Papaya powder produced from drying at 100 °C for 120 min yielded the most due to its high moisture content. Increasing the drying time to 140 min resulted in the highest lightness (L* value) compared to other samples. Drying at 120 °C for 140 min increases solubility, increase hygroscopic and bulk density, and retains maximum retention of ascorbic acid, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities (ABTS assay) compared to other drying times and temperatures. Drying at 110 °C for 140 min retained a higher beta-carotene content than other samples. Results show a significant positive correlation between TFC and DPPH (r = 0.852), and ABTS (r = 0.719) at p < 0.01, contributing to papaya powder's high antioxidant compounds and activity. Scanning electron microscope (SEM) analysis showed that particles at 120 °C for 140 min were the smallest. This can improve particle morphology, enhancing the exposure and stability of bioactive compounds. In conclusion, drying papaya at 120 °C for 140 min effectively preserves total phenolic content (TPC) and total flavonoid content (TFC), which subsequently enhances the powder's antioxidant activity and functional properties. [ABSTRACT FROM AUTHOR]

The Agaricus bisporus (Button mushroom) stands out as one of the most prolific edible fungi which offers robust flavor and nutrition. Nonetheless, this mushroom contains high moisture levels and intense respiration. Without appropriate postharvest preservation techniques, the button mushroom readily experiences browning and senescence. To ensure optimum quality, prompt cooling and appropriate storage conditions are essential. This present research investigated the postharvest quality of button mushrooms stored in a controlled atmosphere (CA) with different initial gas compositions. The findings revealed that button mushrooms in the CA group demonstrated considerable enhancements in appearance and overall quality, effectively delaying browning and senescence compared to those in the control group. The optimal gas composition is 1–3% O2 and 15–17% CO2 (CAII), which effectively inhibited the expression of polyphenol oxidase (PPO)- and lactase (LAC)-related genes in the button mushroom, maintaining a high L* value. Furthermore, the application of 1–3% O2 and 15–17% CO2 (CAII) not only preserved visual quality but also extended the postharvest shelf life of the button mushroom by minimizing metabolic activities that contribute to senescence. Moreover, 1–3% O2 and 15–17% CO2 (CAII) storage also reduced the expression levels of genes associated with ethylene synthesis, which is reflected in the gradual decrease in cell membrane permeability. Consequently, this research underscores the critical importance of controlled atmosphere storage in improving the marketability and sustainability of this widely consumed mushroom. [ABSTRACT FROM AUTHOR]

This research analyzed the impact of exposing mung bean sprouts to ultraviolet-C (UV-C) radiation for different periods (2, 5, and 10 min). Treated sprouts were preserved at 5°C and 85-95% relative humidity for 6 days. Irradiation for 10 min effectively reduced fresh weight loss, electrolyte leakage, and microbial count and maintained the firmness of sprouts. It also positively influenced the bioactive components, including antioxidants, total phenols, and protein, potentially providing health benefits to consumers. In addition, prolonged UV-C exposure for 10 min leads to oxidative stress, marked by a rise in malondialdehyde, proline, and hydrogen peroxide content. These compounds assist in stress reduction and preserve secondary metabolites. This research implies that postharvest 10 min UV-C irradiation offers a potential approach to uphold quality while maximizing the nutritional value of mung bean sprouts. [ABSTRACT FROM AUTHOR]

The document "Special Issue: 'Advanced Studies in Maintaining Post-Harvest Quality of Fruits and Vegetables'" published in the journal Horticulturae focuses on new preservation technologies to enhance the quality, safety, and shelf life of fruits and vegetables. It includes articles on physical and chemical preservation technologies, preharvest treatment technologies, and other innovative methods. The research presented in this special issue aims to improve communication and collaboration in the field of horticultural post-harvest preservation technology, benefiting the horticultural industry's healthy development. [Extracted from the article]

Browning limits the shelf life of fresh-cut eggplant. To control browning, organic Thai eggplant cv Chao Phraya is treated with calcium lactate at different concentrations (0.5, 1.0, 1.5 and 2.0%) a 5 minutes dip before storage at 10°C with 90% relative humidity for 4 days. Water dip and no dip serve as control treatments. Calcium lactate at 0.5-1.0% remarkably reduces browning to a moderate degree; in contrast, higher calcium lactate concentrations, water dip and no dip treatments caused very severe browning at the end of storage. Browning severity is also manifested as reduced lightness (L*) values and increased brown pigment concentration. The total phenolic content did not change much in response to the 0.5-1.0% calcium lactate treatment, while the other treatments reduced the phenolic content, indicating conversion to brown pigments. Polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL) and peroxidase (POD) were significantly lower with 0.5-1.0% calcium lactate than with other treatments. This supported the reduction of browning by these treatments.

In order to reduce the enzymatic browning of loquat pulp during the pulping process and to maintain the original color of the pulp, the color difference value (ΔE) was used as the main response variable. The effect of six color protectors in protecting loquat pulp from pulping was investigated and the two best performers were selected for the central composite design (CCD) test. Based on this, an investigation was conducted into the effect of composite color protection on the color and the content of nutrition of loquat pulp during storage at 5 ℃ for 28 days. Out of the six color protectors, the results indicated that ascorbic acid and phytic acid had a significant impact on color protection, and the optimal ratio included 0.332% ascorbic acid, 0.065% phytic acid. The verification test showed the average ΔE of loquat pulp after composite color protection was 6.70, which closely aligned with the predicted value at 97.31% agreement. The storage test showed that the composite color protection could effectively retard the decrease in L*, a*, b* and ΔE values of loquat pulp, while reducing the loss of total sugar, ascorbic acid and total phenol, and the increased of titratable acid content, to maintain the nutrition of the pulp. This study could provide technical reference for the processing and utilization of loquat.

In order to solve the enzymatic browning phenomenon in the pulping unit of Lonicera caerulea fruits and improve its utilization value. The main phenolic substrates involved in the enzymatic browning reaction in the pulping process of Lonicera caerulea fruits and the inhibition ability were investigated, and the interactions between phenolic substrates and epicatechin on the reaction of polyphenol oxidase (PPO) were analyzed and its mechanism of enzymatic browning was also determined. The three most effective inhibitors were further selected by comparing the effects of ascorbic acid, L-cysteine, calcium chloride, EDTA-2Na, and citric acid additions on the browning inhibition rate. The results showed that epicatechin was the primary influencing factor involved in enzymatic browning in the pulping process of Lonicera caerulea fruits, and the quenching mechanism of epicatechin on PPO was static quenching. The response surface optimization test determined the optimal combination of composite inhibitors as 0.11% ascorbic acid, 0.11% L-cysteine, and 0.08% EDTA-2Na, and the browning inhibition rate of Lonicera caerulea fruits juice under this condition was 93.17%. It indicates that the above composite inhibitors can inhibit the enzymatic browning in the pulping process of Lonicera caerulea fruits.

Polyphenol oxidase (PPO) plays a key role in the enzymatic browning process, and this study employed Gaussian-accelerated molecular dynamics (GaMD) simulations to investigate the catalytic efficiency mechanisms of lotus root PPO with different substrates, including catechin, epicatechin, and chlorogenic acid, as well as the inhibitor oxalic acid. Key findings reveal significant conformational changes in PPO that correlate with its enzymatic activity. Upon substrate binding, the alpha-helix in the Q53-D63 region near the copper ion extends, likely stabilizing the active site and enhancing catalysis. In contrast, this helix is disrupted in the presence of the inhibitor, resulting in a decrease in enzymatic efficiency. Additionally, the F350-V378 region, which covers the substrate-binding site, forms an alpha-helix upon substrate binding, further stabilizing the substrate and promoting catalytic function. However, this alpha-helix does not form when the inhibitor is bound, destabilizing the binding site and contributing to inhibition. These findings offer new insights into the substrate-specific and inhibitor-induced structural dynamics of lotus root PPO, providing valuable information for enhancing food processing and preservation techniques. [ABSTRACT FROM AUTHOR]

The rising demand for freshly cut agricultural produce like bananas, apples, pears, potatoes, and roots due to health concerns and modern lifestyles has heightened awareness of their susceptibility to browning, which diminishes their appeal and contributes to food waste. The present study explored the efficacy of natural anti‐browning agents in prolonging the quality and shelf‐life of freshly cut green banana slices. The bananas underwent treatment with normal water (NW), lemon juice (LJ), and coconut water (CW), and the changes in physicochemical properties, such as browning intensity, color, firmness, total soluble solid (TSS), total phenolic content (TPC), total flavonoid content (TFC), and also microbial attributes, were evaluated during their storage at 4 ± 1°C for 12 days. The results demonstrated significant enhancements in treated samples compared to untreated ones. While normal water and lemon juice‐treated banana slices exhibited visual browning during storage, coconut water immersion proved superior in maintaining visual appeal, whiteness, and lightness while delaying yellowing and browning. Coconut water‐treated samples also displayed firmer texture (0.75 kg), lower TSS (5.67 °Brix), and reduced weight loss (9.14%) after 12 days, in contrast to samples subjected to lemon juice and normal water treatments which showed lesser texture (0.68 kg, 0.58 kg), higher TSS (5.87 °Brix, 6.10 °Brix), and greater weight loss (11.76%, 16.09%), respectively. Furthermore, coconut water‐treated samples retained higher levels of total phenols (392.67 mg GAE (gallic acid equivalent)/100 g FW (fresh weight), total flavonoids (55.67 mg QE (quercetin equivalent)/100 g FW), and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging activity (38.68%). Coconut water treatment also significantly suppressed polyphenol oxidase (PPO) activity (14 U/g) compared to lemon juice (16 U/g) and normal water (26 U/g) treatments, and untreated samples (133 U/g) after 12 days. Additionally, microbial load remained within acceptable limits for all samples, with coconut water‐treated samples showing the lowest values. Thus, coconut water is a promising natural solution for inhibiting browning and preserving the quality of fresh‐cut green banana slices during storage. [ABSTRACT FROM AUTHOR]

Presented in the form of a fairy tale, this article employs engaging imagery and accessible language to guide readers through the scientific principles underlying the colorful appearance and common color-changing phenomena in plant-based foods. By exploring the structure and properties (such as solubility and stability) of major plant-based food pigments like chlorophyll, carotenoids, and anthocyanins, readers gain a deeper understanding of the reasons behind these phenomena. Additionally, the article enhances comprehension of enzymatic browning principles and prevention methods, while fostering a nuanced understanding of food additives such as coloring agents. [ABSTRACT FROM AUTHOR]

The prevention of enzymatic browning through the application of tyrosinase inhibitors has become a research focus in food industry. In this article, multi-spectroscopic and computational simulation was used to study the binding behavior and inhibition mechanism of aloin to tyrosinase. It found that aloin was an effective inhibitor of tyrosinase activity with a mixed type inhibition. Aloin bound to tyrosinase through hydrophobic forces, causing a conformational change in the enzyme and resulting in its inherent fluorescence being quenched. There was a binding site for aloin with tyrosinase and the binding constant was approximately 104 L mol−1. Molecular simulations showed that hydrophobic and hydrogen-bonding forces were the main factors in the binding of aloin to tyrosinase. Aloin introduced into the active site of tyrosinase interacted with amino acid residues Gly281, His244, Val283, Ala286 and His263, occupying the catalytic center of the tyrosinase and blocking substrate entry, resulting in tyrosinase inhibition. Molecular dynamics simulation further indicated that the binding of aloin changed the secondary structure of tyrosinase with little effect on the microenvironment of tyrosinase amino acid residues. This study offers new understanding of the mechanisms of activity of aloin as a tyrosinase inhibitor. [ABSTRACT FROM AUTHOR]

Enzymatic browning is a major cause of postharvest quality loss in fruits/vegetables. Heat and chemicals are conventionally employed to prevent enzymatic browning. However, the demand for fresh-like fruit/vegetable products processed without chemical additives has shifted the paradigm towards natural antibrowning agents. Consequently, essential oils, hydrosols, honey, and plant extracts have received considerable attention as natural antibrowning agents during the last 4–5 years owing to the ability of their active constituents (flavonoids, phenolic acids, antioxidative peptides, thiol compounds, and/or carboxylic acids) to affect oxidative enzymes by (i) complexing at various sites through hydrogen, van der Waals, π-sigma/π-π stack, electrostatic, and hydrophobic interactions, (ii) chelating metals at their active sites, and (iii) making conditions unfavourable for their activity as well as due to their ability to behave as membrane integrity promotors, substrate synthesis suppressors, and oxygen quenchers depending on the source, concentration, target fruit/vegetable, and processing conditions. However, their application in fruit/vegetable processing is challenging. For instance, plant extracts display high variability and lower effectiveness than synthetic antibrowning agents, while essential oils and hydrosols exhibit strong odours, limited solubility, and volatility. This article reviews the most recent studies on essential oils, hydrosols, honey, and plant extracts to provide an overview of the modes of action of natural antibrowning agents and highlight challenges associated with their utilisation. [ABSTRACT FROM AUTHOR]

Fresh-cut sweet potatoes are popular among consumers for their freshness and convenience. However, rapid browning and oxidative damage under stress significantly degrade their storage quality. This study aims to evaluate the effects of citric acid (CA) treatment on maintaining the quality of fresh-cut sweet potatoes during storage and to explore the underlying mechanisms. Fresh-cut sweet potatoes were immersed in 1% (w/v) CA for 10 min, with water treatment as the control (CK), and stored at 4 °C for 8 d. Physicochemical parameters were evaluated every 2 d. After 8 d of storage, CA-treated samples exhibited significantly lower total colony count (3.34 lg CFU g−1), soluble sugar content (1.52%), and lignin content (2.62 OD280 g−1) compared to the CK group (P < 0.05), and better maintained color values. Additionally, CA treatment inhibited the increase in browning-related enzyme activities (phenylalanine deaminase, polyphenol oxidase, peroxidase) and the accumulation of browning products (total phenolics, soluble quinones), resulting in a browning index 8.15% lower than the CK group at the end of storage. The CA-treated fresh-cut sweet potatoes also exhibited lower malondialdehyde content (0.58 µmol g−1) and lipoxygenase activity (3.19 U g−1), while showing higher activities of antioxidant enzymes such as catalase and ascorbate peroxidase, and enhanced free radical scavenging capacity, indicating that CA treatment helps mitigate cutting-induced oxidative stress. In conclusion, our findings highlight the significant potential of CA treatment in preserving the storage quality of fresh-cut sweet potatoes and provide new insights into its regulatory mechanisms. [ABSTRACT FROM AUTHOR]

Cherimoya (Annona squamosa L.) is a nutrient-rich fruit. However, it is not easy to store because of its susceptibility to browning. In order to prolong the storage period of cherimoya, the fruit was treated with chlorine dioxide (ClO2) at different concentrations (20, 40, 60, 80, and 100 mg L−1) and stored at 15 °C for 8 days. The quality and biochemical indexes of the fruit were investigated using a chromameter, high-performance liquid chromatography and scanning electron microscopy, etc. The results showed that all the treatments with various concentrations of ClO2 could delay the increase in the browning index, loss of weight, and decrease in hardness. Meanwhile, ClO2 treatment effectively reduced the consumption of starch, titratable acids, and phenolics as well as inhibited the polyphenol oxidase (PPO) activity and enzymatic oxidation. It can be seen from the Fourier transform infrared spectrum (FTIR) that the C=O stretching peak at 1731 cm−1 disappeared at a ClO2 concentration of 60 mg L−1. We think the ClO2 treatment may inhibit the oxidation of phenol to quinone. According to the Arrhenius formula, the values of the apparent activation energy (Ea) for enzymatic browning reaction were estimated. The Ea with catechol in cherimoya pericarp and flesh were 67.00 and 47.83 kJ mol−1, respectively. It was found that the phenolic enzyme reaction with catechol has a much smaller Ea and a higher affinity for PPO. Therefore, treatment with ClO2 at a suitable concentration for cherimoya stored at 15 °C could effectively maintain fruit quality and prolong the storage period; the most appropriate concentration is 60 mg L−1. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South-Central Minzu University (Natural Science Edition) is the property of Journal of South-Central Minzu University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Enzymatic browning, catalysed by the enzyme polyphenol oxidase in fruit and vegetables, limits the efficient use of natural resources and promote food waste. Plums are a popular fruit with consumers around the world and are considered an important raw material in the food industry. Plums are very susceptible to enzymatic browning due to their high phenolic compound content and climacteric nature. The aim of this study is to purify the polyphenol oxidase enzyme from Sarali plum (Prunus domestica) and to determine its biochemical properties, kinetic parameters, pH and thermal stability and inhibition. In this study, polyphenol oxidase enzyme was purified 22.54-fold by affinity chromatography using Sepharose-4B-l-Tyr-p-amino benzoic acid affinity gel. The purity and molecular mass of the enzyme were determined by SDS-PAGE and non-denaturing PAGE (native PAGE). The molecular mass of the enzyme was estimated to be 72.44 kDa by SDS-PAGE. The enzyme was confirmed as PPO by native PAGE as a single band. Kinetic characterization studies were conducted for both catechol and 4-methyl catechol substrates. The optimal pH and temperature for both substrates were found to be 7.0 and 20 °C, respectively. The thermal stability of PPO was investigated, and it retained about 90% of its activity for 90 min at 4 °C. The determination of KM and Vmax was carried out using the Lineweaver–Burk plot. The substrate specificity (Vmax/KM) values for catechol and 4-methyl catechol were determined as 790.91 ± 37.34 and 492.06 ± 13.75 respectively. The enzyme exhibited the best activity towards catechol substrate. IC50, Ki constant and inhibition types were determined for various anti-browning agents on PPO enzyme. Ascorbic acid, l-cysteine, citric acid, salicylic acid and tartaric acid effectively inhibited PPO activity. [ABSTRACT FROM AUTHOR]

Coffee bean oxidation is associated with enzymatic and non-enzymatic browning, the degradation of desirable aromatic compounds, the development of undesirable flavors, increased susceptibility to microbial spoilage, and volatile compound losses. This study investigated natural dry process (DP) and honey process (HP) green coffee beans stored in GrainPro® bags for 0, 5, 10, and 20 days under accelerated storage conditions at 30 °C, 40 °C, and 50 °C with relative humidity of 50%. A kinetic model was used to estimate the shelf life of the green coffee beans. DP recorded durability of 45.67, 29.9, and 24.92 days at 30 °C, 40 °C, and 50 °C, respectively, with HP 60.34, 38.07, and 19.22 days. Partial least squares (PLS) analysis was performed to build the models in order to predict the shelf life of coffee based on peroxide (PV) and thiobarbituric acid reactive substances (TBARS) values. In terms of prediction with leave-one-out cross-validation (LOOCV), PLS provided a higher accuracy for TBARS ( R 2 = 0.801), while PV was lower ( R 2 = 0.469). However, the auto-prediction showed good agreement among the observed and predicted values in both PV ( R 2 = 0.802) and TBARS ( R 2 = 0.932). Based on the variable importance of projection (VIP) scores, the ATR-FTIR peaks as 3000–2825, 2154–2150, 1780–1712, 1487–2483, 1186–1126, 1107–1097, and 1012–949 cm−1 were identified to be the most related to PV and TBARS on green coffee beans shelf life. ATR-FITR showed potential as a fast and accurate technique to evaluate the oxidation reaction that related to the loss of coffee quality during storage. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agroindustrial Technology / Jurnal Teknologi Industri Pertanian is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

One of the factors precluding potato juice application in the food industry is its propensity for enzymatic browning. The addition of fruit and vegetable concentrates rich in organic acids can reduce unfavorable changes in the color of potato juices and influence the content of biologically active compounds. This study aimed to investigate the effect of the addition of natural fruit and vegetable concentrates to potato juices on their color and on the composition and contents of anthocyanin pigments isolated from them. The color, composition and amount of anthocyanins in potato juices and dyes were determined using HPLC-DAD and UHPLC MS/MS liquid chromatography. It was found that the juices without concentrate addition had, on average, 61% lower total polyphenol content and 63% lower anthocyanin content compared with the juices with added concentrates. The isolated pigments contained, on average, 30–40 times more anthocyanins compared with those isolated from the non-purified juices. Furthermore, the addition of concentrates enabled ca. 3–5 times more effective isolation of anthocyanins compared with the samples without these additives. Potato juices and dyes with the addition of concentrates showed a lighter color that did not change over time, compared with samples without concentrates. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the enzymatic browning phenomenon in the pulping unit of Lonicera caerulea fruits and improve its utilization value. The main phenolic substrates involved in the enzymatic browning reaction in the pulping process of Lonicera caerulea fruits and the inhibition ability were investigated, and the interactions between phenolic substrates and epicatechin on the reaction of polyphenol oxidase (PPO) were analyzed and its mechanism of enzymatic browning was also determined. The three most effective inhibitors were further selected by comparing the effects of ascorbic acid, L-cysteine, calcium chloride, EDTA-2Na, and citric acid additions on the browning inhibition rate. The results showed that epicatechin was the primary influencing factor involved in enzymatic browning in the pulping process of Lonicera caerulea fruits, and the quenching mechanism of epicatechin on PPO was static quenching. The response surface optimization test determined the optimal combination of composite inhibitors as 0.11% ascorbic acid, 0.11% L-cysteine, and 0.08% EDTA-2Na, and the browning inhibition rate of Lonicera caerulea fruits juice under this condition was 93.17%. It indicates that the above composite inhibitors can inhibit the enzymatic browning in the pulping process of Lonicera caerulea fruits. [ABSTRACT FROM AUTHOR]

Greening and enzymatic browning are important factors causing post-harvest losses in potatoes. Although they are two different biological processes, there are some common inhibitors between them. Whether there is a correlation between the two has yet to be studies. In this research, we conducted transcriptome analysis of non-greening and greening potatoes, identifying several browning-related genes (polyphenol oxidase genes and peroxidase genes). Compared to non-greening potatoes, greening potatoes exhibited a greater browning degree. And calcium chloride (CaCl2) can inhibit both greening and enzymatic browning. However, the inhibitory effect on potatoes was weakened when treated simultaneously with SA synthesis inhibitor and CaCl2, indicating that CaCl2 can regulate potato greening and browning by affecting internal SA synthesis. Additionally, exogenous SA treatment of potato tubers can also inhibit enzymatic browning. Our study not only demonstrated that CaCl2 and SA can serve as a bridge connecting the potato greening and enzymatic browning, but also provided important references for the development of novel co-inhibitors.

The editorial "Advanced Technologies for Enhancing Structure and Functions of Films and Coatings" discusses current trends in sustainable and multifunctional biopolymer-based films and coatings. Nanotechnology plays a crucial role in improving mechanical strength and barrier properties, while edible coatings with natural extracts offer protection and extended shelf life in food applications. The contributions in this editorial focus on enhancing mechanical, antioxidant, and preservation properties of food packaging and coatings through innovative technologies and materials. [Extracted from the article]

Peaches are an ancient fruit in China, with great nutritional and commercial value. Peach fruit is a typical respiratory climacteric fruit, which is prone to browning within a short period of time after harvesting, and rapid browning and high browning degree occur during peach processing, which are difficult to control, affecting the quality and economic value of the fruit. At present, systematic research on the characteristics and mechanism of peach browning is lacking, as well as effective control techniques and methods. In this paper, the current status of research on the characteristics and mechanism of and the key factors for enzymatic browning in peach fruit is reviewed, and the techniques used for its control are summarized, aiming to provide a reference for the regulation of enzymatic browning during peach storage and processing and consequently to promote the quality improvement of fresh and processed peach products.

Sea buckthorn juice has high nutritional value and a rich flavor that consumers enjoy. Traditional sea buckthorn thermal processing (TP) technology has problems such as low juice yield, poor quality, and poor flavor. Sea buckthorn berries are processed using a technique combining pulsed electric field (PEF) and high-pressure processing (HPP) to increase juice yield and study its impact on the quality and volatile aroma of sea buckthorn juice. Results have show that, compared with TP, under the condition of PEF-HPP, the juice yield of sea buckthorn significantly increased by 11.37% (p > 0.05); TP and PEF-HPP treatments could effectively kill microorganisms in sea buckthorn juice, but the quality of sea buckthorn juice decreased significantly after TP treatment (p > 0.05), whereas PEF-HPP coupling technology could maximally retain the nutrients of sea buckthorn juice while inhibiting enzymatic browning to improve color, viscosity, and particle size. The flavor of sea buckthorn juice is analyzed using electronic nose (E-nose) and gas chromatography–ion mobility spectrometer (GC–IMS) techniques, and it has been shown that PEF-HPP retains more characteristic volatile organic compounds (VOCs) of sea buckthorn while avoiding the acrid and pungent flavors produced by TP, such as benzaldehyde, (E)-2-heptenal, and pentanoic acid, among others, which improves the sensory quality of sea buckthorn juice. PEF-HPP technology is environmentally friendly and efficient, with significant economic benefits. Research data provide information and a theoretical basis for the sea buckthorn juice processing industry. [ABSTRACT FROM AUTHOR]

In order to prolong the storage period of fresh-cut lettuce, provide theoretical basis for the application of calcium lactate in the processing technology of fresh-cut lettuce, in this study, lettuce was used as the test material to investigate the physiological mechanism of different concentrations(0(CK), 1.5, 3.0,4.5 g/L) of calcium lactate(CAL) treatments in controlling the browning of fresh-cut lettuce. The evaluation indexes included the physiological characteristics such as weight loss rate, browning index(BI), chlorophyll content, relative conductivity, malondialdehyde(MDA) content, and vitamin C(Vc) content, polyphenol oxidase(PPO) activity, peroxidase(POD) activity, phenylalanine ammonia lyase(PAL) activity, and the changes in antioxidant substances such as the acitivities of ascorbic acid(Vc), polyphenol oxidase(PPO), peroxidase(POD), and phenylalanine ammonia lyase(PAL) and the total phenolic content of fresh-cut lettuce during storage. The effect of different concentrations of CAL on the storage quality of fresh-cut lettuce was analyzed. The results showed that the moisture content of fresh-cut lettuce treated with CAL was higher until the eighth day of storage; however, the fresh-cut lettuce treated with the control(CK) appeared wilting and it was two days earlier than the lettuce treated with 3.0 g/L and 4.5 g/L of CAL. Compared to the control, different concentrations of CAL could delay the decomposition of chlorophyll, maintain the relative integrity of the cell membrane, reduce the loss of Vc, suppress the activities of PPO, POD, and PAL, and slow down the decrease in total phenolic content. The effect of 3.0 g/L of CALtreatment was the most significangt, the activities of PAL, PPO, and POD in the 3.0 g/L CAL treatment were 30.1%, 45.5%, and 24% lower, respectively, than those in the control group on the tenth day of storage. Additionally, the total phenol content was 1.6 times that of the control, acting as an antioxidant to alleviate enzymatic browning of fresh-cut lettuce. The 3.0 g/L CAL treatment was more beneficial in delaying enzymatic browning, maintaining good physiological characteristics and antioxidant quality of fresh-cut lettuce, preserving its commercial value during the ten-day storage period, the shelf life of the treatment was four days longer than that of the control. [ABSTRACT FROM AUTHOR]

The enzymatic browning of fresh-cut lotus rhizomes has been studied extensively at present, but few people pay attention to the quality deterioration of whole lotus rhizomes caused by non-enzymatic browning. In this study, we first screened the compound inhibitors for the blackening of lotus rhizome by color difference and sensory properties and then investigated the effects of blackening compound inhibitors on storage quality and shelf life of lotus rhizome. Results showed that the combination of 0.9% sodium alginate, 2% EDTA-2Na, 5% glycerol and 0.5% potassium sorbate (ENCI-4) had the best color difference and sensory properties of the lotus rhizome. Moreover, after 60 d of low-temperature storage, it was found that the sensory scores, SSC and total phenols contents of the lotus rhizomes treated with ENCI-4 were significantly higher than those in control groups (p < 0.05), while the color difference, total acid, MDA contents, total bacterial, mold and yeast count were significantly lower than those in control groups (p < 0.05). Besides, by comparing the storage quality of bruised lotus rhizomes (CK-1) and mud-treated lotus rhizomes (CK-2), it was found that the formation of epidermal blackening in CK-2 would accelerate the browning and aging rates of lotus rhizomes, thereby having a more negative impact on its storage quality, while the shelf life of lotus rhizome could be significantly extended after ENCI-4 treatment. Overall, the blackening compound inhibitor formula proposed in this study can effectively extend the shelf life of the whole lotus rhizome. [ABSTRACT FROM AUTHOR]

Tender coconut water (TCW) processing has been a challenge and is often accompanied by challenges such as beneficial bioactive compound deterioration and enzymatic and non‐enzymatic browning initiation. Fresh TCW was treated with a combination of pressure (350–550 MPa) and treatment time (3–7 min). This study unveiled the potency of high‐pressure processing (HPP) in reducing undesirable enzyme activity, such as polyphenol oxidase (PPO) and peroxidase (POD) activity in TCW by up to 36.472% and 30.606%, respectively. The maximum loss of vitamin C was reported to be 7.84% at 550 MPa/7 min compared to the untreated one, which is very acceptable in terms of quality retention. The total phenolic content and antioxidant activities were well retained and increased in the HPP‐treated TCW samples. Similarly, the total and reducing sugar reduction was within 20%–25%. The findings of this investigation demonstrated the effectiveness of high‐pressure processing in preserving quality and reducing the activity of enzymes that cause deterioration in TCW. Moreover, the aerobic plate count (APC) and yeast and mold count (YM) were decreased significantly (p < 0.05) after 450 MPa/5 min treatment. Practical applications: Over the years, the food industry has been facing a consistent challenge in perishable product processing (juices, milk, meat, etc.) to extend its shelf‐life while keeping its nutritional and sensory properties intact. This study presented a significant insight into TCW processing regarding enzyme, microbial inactivation, and nutritional property preservation using HPP technology. Moreover, from a quality perspective, this work enables the HPP‐treated TCW to be as close to a fresh one without any preservative addition. HPP technique is believed to appeal to industries that seek a green alternative technique to thermal processing (which makes processed foods unacceptable among consumers) to produce minimally treated foods on a commercial scale. [ABSTRACT FROM AUTHOR]

Enzymatic browning, occurring on the cut surfaces of many popular fresh-cut fruit and vegetables due to wounding and the activity of endogenous polyphenyloxidase enzymes, is considered as the main reason for their rejection by consumers. In this study, water extracts were obtained from seeds of cabbage, sinapis, and wild rocket at 10 and 20% w/w seed:water ratios (SWE) and analyzed for total phenolic compounds (TPC) and antioxidant capacity (AC). The extract was then applied on cut surfaces of mid rib segments of lettuce leaves for 1 or 3 min. The segments were stored at 7 °C for 14 days. The SWE's inhibitory capacity on enzymatic browning were measured by CIELAB color coordinates L* a* and b* and expressed as second derivatives, their % inhibition and different indices. An additional visual acceptance measurement and calculation of shelf life was also performed. The seed extracts of cabbage at 10–20% and wild rocket at 20% showed the highest anti-browning efficacy (comparable to 25 mM potassium metabisulfite control) along with TPC and AC. A high % of seed:water extract and increased exposure time led to a considerable increase in shelf life, visual score, % inhibition of browning or whitening index of the extracts of all seed sources. Chromatometric outcome data clearly showed that the visual data were more accurate than the chromatometric procedure (L*, a*, b* values, their derives ΔE, h°, C, Δh° and ΔC or calculated indices), although the latter could detect the differing degrees of browning development or its inhibition in treated and control segments during storage. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ber fruit (Zizyphus mauritiana Lamk) contains abundant polyphenols and is highly susceptible to enzymatic browning after harvest. In order to reduce browning and maintain fruit quality of ber fruit, a factorial experiment was conducted in a completely randomized design with four replications. Experimental treatments included control, Zataria multiflora essential oil (ZEO) (0.5%), ZEO (1%), Aloe vera gel -based (20%) enriched with sesame oil 1%, honey 1% (ASH), ASH + ZEO (0.5%), ASH + ZEO (1%) and storage time (0, 7, 14, 21 and 28 days) at 6 ± 1°C and relative humidity of 90±5%. The results showed that edible coating application had significant effect on the quality characteristics of the ber fruit during storage. The combination of ASH with ZEO (0.5%), as an edible coating, significantly alleviated enzymatic browning by reducing PPO and POD activities on fruit during 28 days of storage. Fruits treated with ASH with ZEO (0.5%) reduced browning index (70%) compared to the control; while increased total phenol content and antioxidant activity (18.14%, and 31.16%, respectively) compared to the control after 28 days of storage. Also, ASH in combination with ZEO (0.5%) treatment decreased electrolyte leakage and malondialdehyde (19.7%, and 17.8%, respectively) compared to the control after 28 days of storage. These results indicated that ASH edible coating in combination with ZEO (0.5%) can be a useful method for delaying ripening and senescence, extending the storage life of ber fruit. [ABSTRACT FROM AUTHOR]

Food browning is an undesirable phenomenon that alters sensory properties and nutritional value of fresh-cut produces, which had a significant economic impact owing to decreased customer acceptability. In this study, the effect of selected spices including cinnamon bark, clove, coriander seed, cumin, fennel seed and Sichuan pepper on iceberg lettuce polyphenol oxidase (PPO) inhibition was investigated to replace synthetic browning inhibitor that often used by food manufacturers. Iceberg lettuce PPO has an enzyme activity of 13677.04 ± 21.00 EU/mL, using pyrocatechol as substrate. Ascorbic acid was used as the synthetic inhibitor of Iceberg lettuce PPO and it acted as a mixed inhibitor with the IC50 of 4.20 ± 0.19 mM. Among all the browning inhibition effect of the selected spices on Iceberg lettuce PPO, cinnamon bark was the best inhibitor among the six selected spice extracts, with the inhibition percentage of 32.39 ± 1.47 % inhibition was determined, followed by fennel seed (16.93 ± 1.47 %), Sichuan pepper (14.24 ± 0.83 %), cumin (13.72 ± 1.35 %), coriander seed (9.85 ± 0.75 %), and clove (9.64 ± 0.47 %) at 2.0 mg/mL. The present findings suggested the potential to expand the application of the spices to be used as food-based anti-browning inhibitors directly on the surface of iceberg lettuce as well as other fresh-cut produces or used as active ingredient of enzymatic browningbased active packaging of fresh-cut produces. [ABSTRACT FROM AUTHOR]

Sugarcane juice is a popular beverage and is also processed to produce sugar. The polyphenol oxidase (PPO) in sugarcane juice causes enzymatic browning and makes the process of sugar production complex and cumbersome. Storage of sugarcane juice is also hampered by the high sugar content and rapid microbial fermentation. The present research assessed the potential of lemon juice (LJ) and ginger extract (GE) as natural inhibitors of PPO. Enzyme kinetics and the mechanism of inhibition of LJ and GE were studied. Primary investigation was carried out using molecular docking approach to assess the inhibitory potential of LJ and GE and to determine the nature of interaction between the enzyme and inhibitors. Extracts were used as inhibitors and studies revealed that both reduced the PPO activity. Subsequently, pure bioactive inhibitors such as ascorbic acid, citric acid, and 6‐shogaol present in these natural extracts were used to study the mode of inhibition of PPO. Citric acid decreased PPO activity by lowering pH, while ascorbic acid was found to be a competitive inhibitor of PPO with a Ki of 75.69 µM. The proportion of LJ and GE required in sugarcane juice was optimized on the basis of browning index and sensory acceptance. Further, the sugarcane cane juice after inhibition of PPO under optimized conditions was spray dried and evaluated for reconstitution properties. The product formulated in the present study is a new and effective approach to address quality‐compromising issues associated with long‐term storage of cane juice. [ABSTRACT FROM AUTHOR]

The trapiá, although it is a species present in almost the entire Brazilian territory, has limited consumption due to the absence of commercial plantations and general unawareness of its properties, aggravated by the difficulty of processing due to rapid enzymatic browning that affects the pulp when handled. In this study, the influence of enzymatic inactivation through thermal blanching on the changes in luminosity, bioactive compounds, and antioxidant activity of trapiá pulp was evaluated. Blanching showed optimal effects when the thermal process was applied for a duration of 15 min, as confirmed by the qualitative determination of peroxidase (POD), indicating the interruption of enzymatic activity. The study of instrumental luminosity kinetics (color parameter) of the sample without thermal blanching treatment (control) and with blanching indicated a degradation process over time governed by a first-order model. The thermal process influenced the levels of bioactive compounds, resulting in increased flavonoids, anthocyanins, and β-carotene. Blanching also led to an increase in antioxidant activity measured by ABTS and DPPH methods, with a significant increase in DPPH radical scavenging activity, reaching 96% higher than the unblanched pulp. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the effectiveness of preharvest fertigation using calcium thiosulfate (CaTS) and potassium thiosulfate (KTS) to enhance the shelf life of bell peppers was investigated. The nutrient solution was enriched with KTS (either 0.26 or 0.53 mM of a commercial formulation) or CaTS (0.66 mM of a commercial formulation), and compared to a commercial source-based nutrient solution as a control. Fruit quality attributes and the activity of key enzymes involved in oxidative stress defense, enzymatic browning, cell wall degradation, and membrane lipid degradation were investigated for 30 days of storage. Results showed that CaTS and KTS treatments preserved protein (a secondary energy reserve) and proline content, and enhanced the fruit's PSII activity throughout storage. Despite increased phenylalanine ammonia-lyase activity, CaTS and KTS fertigation did not affect polyphenol oxidase activity. CaTS and KTS fertigation increased the activity of five (out of seven) antioxidant enzymes and impaired the activity of one (out of two) cell wall hydrolytic enzyme. CaTS was the most effective treatment, followed by KTS (0.53 mM), in causing these promotive effects. In conclusion, preharvest application of CaTS (0.66 mM) and KTS (0.53 mM) prolonged the postharvest life and delayed senescence of bell pepper fruits by preserving fruit weight, firmness, and photosynthetic performance, as well as enhancing the antioxidant defense system.

This study investigated the changes in the quality-related parameters and physicochemical properties of yam (Dioscorea alata L. var. Dasan) harvested after 260 d. The stem tip, middle, and bottom sections of yams were stored at room temperature (20 °C ± 2 °C) for 16 weeks. Samples were taken every 2 weeks and analyzed to determine the changes in physicochemical properties during storage. α-Amylase and PPO activities were highest in the stem tip section. A positive correlation between enzyme activities and storage time was observed in all groups. polyphenol oxidase (PPO) peaked during week 10 of storage and gradually decreased. No significant correlation was found between α-amylase activity and starch content. Moreover, similar to free sugar content, α-amylase activity reached its maximum value during week 14 of storage. All sections of the yams showed reductions in cooking loss rates with the prolongation of storage and reached their minimum cooking loss during week 10 of storage. During the storage, the middle sections of the yams exhibited the most consistent quality, presenting minimal changes in hardness and color stability and the lowest rate of cooking loss. The quality of yam tubers, particularly in enzymatic browning after slicing, post-cooking hardness, cooking loss, and free sugar content, was affected by fluctuations in α-amylase and PPO activities during storage. Therefore, these factors should be considered when evaluating quality and determining optimal storage and handling procedures. The results of this study may serve as a reference for determining the quality of yams during postharvest storage and are important for companies and researchers seeking to optimize yam storage for maximum yield and profitability.

Objective: This study aimed to extend the storage period of fresh-cut Lanzhou lily. Methods: Fresh-cut Lanzhou lily was used as raw materials. Following fresh-cut processing, the raw materials were soaked with 0 (CK), 1, 5, and 10 g/L of SI solution to analyze the quality changes of fresh-cut Lanzhou lily during storage. Results: The soaking treatment with 10 g/L of SI could better maintain the brightness of freshly cut Lanzhou lily. At 21 days of storage, the concentrations of malondialdehyde, soluble sugar, and browning were, respectively, 45%, 8%, and 23% lower than those of the CK group. The SI-treated group had significantly decreased polyphenol oxidase, peroxidase, and lipoxygenase (97.22, 0.09, and 11.89 U/g, respectively) activity at the end of storage compared to the CK group (P＜0.05). In addition, electronic nose analysis showed that SI treatment modulated the flavor of fresh-cut Lanzhou lily during storage. Conclusion: SI soaking treatment is a simple, economical, and safe post-harvest treatment technique that can delay the oxidative browning of fresh-cut Lanzhou lily and thus maintain its quality during storage.