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Background: The color of green tea is an important quality indicator. In recent years, shading of tea (Camellia sinensis L.) plants has been widely adopted for green tea production to enhance its green color and umami taste. In this study, we identified factors that influence green tea color by (i) examining variation in the chlorophyll content of fresh new tea shoots among cultivars, cropping seasons, and the degree of shading, (ii) investigating the rate of conversion of chlorophyll to pheophytin during the tea manufacturing process, specifically with steaming duration, and (iii) analyzing the effects of the new tea shoot properties and the steaming process on colorimetric values of the steamed new tea shoots., Results: Multiple regression analysis revealed that three factors contributed to the rate of conversion of each chlorophyll type to pheophytin in steamed new tea shoots (ranked by importance): steaming duration > each chlorophyll type (chlorophyll-a and chlorophyll-b) content of fresh new tea shoots > pH. The colorimetric hue angle (h) value of steamed new tea shoots was influenced by four factors (ranked by importance): steaming duration > total chlorophyll (chlorophyll-a + chlorophyll-b) content in fresh new tea shoots > pH > chlorophyll-a/chlorophyll-b ratio in fresh new tea shoots., Conclusion: Differences in the color of new tea shoots can be explained by the aforementioned four factors. The findings will be useful for cultivar selection, and determining the appropriate degree of shading and steaming duration, to produce high-quality green teas with a good appearance. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Background: Our living environment is being increasingly polluted by petroleum-based plastics and there is an increasing demand for biodegradable food packaging. In this study, the effect of various ultrahigh-pressure (UHP) treatments (0, 200 and 400 MPa) on the microstructure and thermal, barrier and mechanical properties of poly(lactic acid) (PLA)/ZnO nanocomposite films was studied., Results: The film-forming solution was processed using UHP technology. The crystallinity, strength and stiffness of the composite film after UHP treatment increased. In addition, barrier property analysis showed that the UHP treatment significantly (P < 0.05) reduced the oxygen permeability and water vapor permeability (WVP) coefficient of the PLA/ZnO nanocomposite film. Furthermore, the WVP value of the film treated at 400 MPa (50 g kg -1 nano-ZnO content) was the lowest and reduced by 47.3% compared with that of pure PLA film. The improvement in these properties might be due to the interaction between nano-ZnO and PLA matrix promoted by UHP treatment., Conclusions: Therefore, the application of UHP technology on the film-forming solution could improve the crystallinity and functional properties of the nanocomposite film, and has great potential in the production of food packaging films with ideal functions. © 2021 Society of Chemical Industry., (© 2021 Society of Chemical Industry.)

The strategy of adding hydrophobic compounds to bio-based films (usually based on hydrophilic matrices), forming films containing emulsions, is a technique that has been used to improve some physical properties (such as reducing water solubility and water vapor permeability) and / or to impart properties, such as antioxidant and antimicrobial effects by carrying hydrophobic active components that would otherwise be insoluble in hydrophilic matrices. Although Pickering emulsions have been reported as presenting greater stability when compared with surfactant-stabilized emulsions, little is known about the drying stability of Pickering emulsions (which is important for film applications). Anyway, several studies have indicated that Pickering emulsions are interesting systems to improve the water vapor barrier properties of bio-based films and coatings, and to act as carriers of active hydrophobic components. On the other hand, the tensile properties of those films are usually impaired by the presence of Pickering emulsions. The objective of this review is to present recent developments and future perspectives in bio-based films loaded with Pickering emulsions. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Background: Active packaging containing natural flavonoid has recently emerged as a result of its potential to inhibit the oxidation of foods by interacting with it and/or its surrounding environment, with the aim of counteracting oxidation reactions and extending the shelf-life of foods. The plant Spondias purpurea L. is widely found in northeastern Brazil and is known to contain bioactive flavonoids. The present study aimed to obtain a flavonoid-rich fraction from the pulp of S. purpurea L. and incorporate it into the cellulose acetate film to obtain biodegradable films with antioxidant properties., Results: The fractionation in SiO 2 open-column chromatography of the S. purpurea pulp crude extract furnished an antioxidant active fraction containing the flavonols quercetin 3-O-rutinoside and kaempferol 3-O-rutinoside as the major compounds. This active fraction was incorporated (10, 20 and 30 g kg -1 ) into the substance produced with the casting method for cellulose acetate films. The films produced were characterized concerning mechanical properties, water vapor permeability (WVP) and antioxidant activity., Conclusion: The incorporation of the active flavonoid fraction from S. purpurea in the cellulose acetate films decreases WVP and elongation at break, at the same time as increasing antioxidant activity, tensile strength and elastic modulus. Thus, the S. purpurea pulps may be an alternative as a source of antioxidants for use in cellulose acetate films. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Background: The use of damaged beans for starch isolation comprises an end-use alternative for a product that is not accepted by the consumer. For that reason, isolation and modification of Carioca bean starch should be explored and evaluated as a suitable source for biodegradable material. The present study aimed to evaluate the synergism of physical and chemical modifications on Carioca bean starch with respect to improving the properties of biodegradable films. A heat-moisture treatment (HMT) followed by oxidation by sodium hypochlorite was performed and vice versa., Results: Synergism was noted in the starch properties compared to the single modification. When the oxidation was applied first, a higher amylose and carbonyl content was noted. HMT, isolated and as a second modification, caused a more pronounced effect on viscosity profile than the oxidized starch, with an increase in paste temperature and a decrease in viscosity, breakdown and final viscosity., Conclusion: The results obtained in the present study reflect a decrease in water vapor permeability, although a higher tensile strength was noted when oxidation was applied, as a single and as a first modification. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Background: Pullulan is a polysaccharide polymer commonly used to produce edible films. However, pure pullulan film is usually brittle and very hydrophilic, which limit its use in both food and pharmaceutical fields. The objective of this research is to improve the structural and mechanical properties of pullulan film by incorporating globular protein lactoferrin (LF)., Results: The incorporation of LF increased the surface hydrophobicity and decreased the water vapor permeability (WVP) of pullulan film. The presence of low concentrations of LF (< 0.03%) has no significant influence on tensile strength (TS) and elongation at break (EAB) of pullulan film. However, further increase of LF concentration to levels > 0.03% resulted in a film-weakening effect. LF molecules aggregated with each other during the film-producing process, which presented as spherical particles from the observation of microscopy. LF aggregates dispersed homogeneously throughout the pullulan matrix and their size increased with increasing concentration. Analysis from Fourier transform infrared spectroscopy indicated that the secondary structure of LF molecules was modified during the drying process., Conclusions: It is possible to increase the hydrophobicity of pullulan film while maintaining its mechanical properties. The produced composite film can be potentially used for food and medical packaging. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

Background: Steam treatment of shredded, fresh C. maculata (honeybush) plant material improves the aroma of this green herbal tea with a slight impact on color and phenolic content, but the effect on storage stability is not known., Results: Steam-treated (60 s before drying) and untreated (control) dried plant material was stored under normal storage conditions in semi-permeable sachets at 25 °C and 60% relative humidity. Reference samples of treated (steamed) and untreated (control) material were stored at 0 °C in impermeable pouches for maximum retention of quality. The stability of the herbal tea was assessed in terms of sensory profile, phenolic composition and color over a storage period of 6 months. Normal storage conditions resulted in a significant (P < 0.05) decrease in green color, especially in steamed samples. Intensities of fruity and sweet-associated aroma attributes increased progressively during storage, while the opposite was observed for vegetal and cereal-like attributes. These changes in the aroma profile were more pronounced in untreated (control) samples. Individual phenolic content remained stable during storage., Conclusions: Storage of 3 to 6 months may result in a more appealing aroma profile and enhanced product quality, despite loss of green color. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: Starches from four common bean genotypes were characterized and used in the production of biodegradable films. Starches were characterized by their swelling power, solubility, amylose content, granule morphology, relative crystallinity, thermal and pasting properties, and susceptibility to α-amylase hydrolysis. Films were characterized according to their morphology, mechanical and water vapor barrier properties, whiteness and opacity., Result: Depending on the common bean genotype, a great variation on starch properties was found, which, in turn, clearly impacted on the characteristics of the starch-based films. Starches from BRS Pitanga and BRS Pérola genotypes exhibited the highest amylose content and the lowest swelling capabilities. Bean starch from the IPR Uirapuru genotype presented granules with an irregular surface and shape. Starches from IPR Uirapuru and BRS Estilo genotypes provided well-structured biodegradable films, without the occurrence of fissures or cracks. Moreover, starch films containing starch from BRS Estilo genotype exhibited the highest flexibility, permeability and solubility., Conclusion: The morphological, mechanical and water vapor barrier properties of films elaborated with common bean starch vary greatly as a function of the bean genotype used for starch production. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: Aflatoxins are carcinogenic toxins produced by Aspergillus flavus and Aspergillus parasiticus that are found naturally in peanut. It requires extremely high temperatures to eliminate aflatoxins from the nuts. The aims of this study were to investigate the effect of ultra-superheated steam (USS) on the reduction of aflatoxin B 1 (AFB 1 ) accompanying the roasting process and to determine roasted peanut qualities that affected consumer acceptance., Results: Whole peanut kernels were intentionally contaminated by AFB 1 standard solution at the level of 50 ± 10 µg kg -1 before subjecting to USS treatment at 300-400 °C between 10 and 80 s. The high temperature of USS could significantly decrease AFB 1 level to 9.83 ± 3.51, 15.33 ± 2.23 and 8.95 ± 2.32 µg kg -1 when 300 °C for 80 s, 350 °C for 40 s and 400 °C for 40 s were employed, respectively. AFB 1 was reduced as much as 83.86 ± 2.66% when 400 °C for 40 s was applied. The moisture content of treated peanuts was decreased to less than 3% and browning index was developed from 30.96 ± 1.59 to 95.76 ± 7.23., Conclusion: Higher roasting degree was obtained according to the increase in browning index. Oil quality showed that peroxide values and acid values were greatly below the allowance level. USS could effectively decrease AFB 1 and render expectable roasting qualities of peanut. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

Background: Several studies investigated the impact of different cooking techniques on the quality of vegetables. However, the use of the combined air-steam cooking is still scarcely debated, despite the advantages informally referred by professional catering workers. In this study, its optimisation was studied on Brussels sprouts and pumpkin cubes to obtain the best physical (texture, colour) and antioxidant (FRAP, total phenols) response, in comparison to a conventional steaming treatment., Results: Increasing the strength of the air-steam treatment, Brussels sprouts resulted to be softer, less green (higher a* value), richer in phenols and exhibited lower FRAP values than the steamed ones. The air-steamed pumpkin cubes exhibited an equivalent softening degree to that of steamed ones and, under the strongest cooking conditions, a higher antioxidant quality and a yellow darkening (lower b* value). Varying the cooking time and/or temperature, a linear change of force/compression hardness and a* (negative a*: greenness) for Brussels sprouts, b* (yellowness) and total phenol content for pumpkin cubes was observed. A predictive model for these variables was obtained by response surface methodology. The best process conditions to achieve the optimal desirability were also identified., Conclusion: The application of air-steam cooking under suitable time/temperature conditions could be proposed as an alternative method to a traditional steam cooking on Brussels sprouts and pumpkin cubes, being able to preserve or improve their quality. The best air-steam cooking conditions were 25 min at 90 °C for Brussels sprouts and 10 min at 110 °C for pumpkin. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

Background: Nostoc sphaeroides has been used as a highly effective herbal medicine and dietary supplement for thousands of years. The desired dark green colour of fresh N. sphaeroides is converted into an undesirable dark brown during conventional high pressure (HP) steam sterilisation. Radio frequency (RF) sterilisation technology was used in this study to determine its effectiveness in sterilising N. sphaeroides and to achieve better preservation of natural colour and desirable flavour. Sterilisation was carried out using a 6 kW, 27 MHz RF instrument for 10, 20 and 30 min. The degree of microbial kill and the effects of RF sterilisation on colour and flavour were determined and compared with those obtained from HP steam (121 °C, 30 min) sterilisation., Results: The effects of RF sterilisation on colour and flavour (measured using electronic nose) parameters were significantly lower than that in HP steam sterilisation. The RF sterilisation carried out for 20 min achieved logarithmic reduction of bacterial population and met China's national standard while preserving the colour and flavour better., Conclusion: Results of the present study indicated that application of RF sterilisation would improve the quality of sterilised N. sphaeroides and broaden its application in the food and health food industries. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

Background: Dried Thunbergia laurifolia leaves are usually prepared using tray drying, resulting in products that have lost substantial amounts of bioactive compounds and antioxidant activity. The maturity of the raw material, blanching techniques and drying methods were investigated in order to select the best condition to produce high qualities of dried T. laurifolia leaves., Results: The 1st stage of maturity was selected and steam-microwave blanching (SMB) for 4 min was adequate for blanching leading to the maximum recovery of bioactive compounds. The modified Halsey model was the best desorption isotherm model. A new drying model proposed in this study was the best to fit the drying curves as compared to five common drying models. Moisture diffusivities were increased with the increase of drying temperature when combining SMB and heat pump-dehumidified drying. Microwave heat pump-dehumidified drying (MHPD) provided the shortest drying time, high specific moisture extraction rate (SMER) and could reduce drying time by 67.5% and increase caffeic acid and quercetin by 51.24% and 60.89%, respectively., Conclusion: MHPD was found to be the best drying method and provided the highest antioxidant activity and bioactive compounds content, high SMER and short drying time. © 2016 Society of Chemical Industry., (© 2016 Society of Chemical Industry.)