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Carica papaya Linn, known for its limited shelf life, typically relies on conventional cold storage (CS) methods to prolong freshness. However, being a fruit sensitive to chilling, papaya exhibits low tolerance to cold conditions, making it susceptible to chilling injury during CS. This study was undertaken to explore the correlation between postharvest treatment using 1‐methylcyclopropene (1‐MCP) and geranium oil (GO) and the antioxidant responses of papaya against oxidative stress during CS. Various treatments were administered, incorporating different concentrations and durations of exposure. The specified concentrations for 1‐MCP and GO were 300 and 600 mg/L, and 2% and 4% (v/v), respectively, with exposure durations of 30 and 60 min. Over a 16‐day period, the fruits underwent assessments for antioxidant activity, related enzyme activities, hydrogen peroxide content, and superoxide anion production rate at 4‐day intervals. Both 1‐MCP and GO treatments enhanced total phenolic and total flavonoid content, DPPH scavenging antioxidant capacity, and notably improved the activities of SOD, CAT, APX, and POD enzymes. This enhancement in antioxidant capacity and enzyme activities effectively mitigated the rise in reactive oxygen species levels in the fruits. The study revealed that 1‐MCP treatment with higher doses and longer exposure times yielded superior outcomes, while GO treatment with higher doses and shorter exposure times produced favorable results compared to longer exposure times. Considering cost‐effectiveness and time efficiency, a more comprehensive exploration of the synergistic effects of 1‐MCP and GO may be essential to optimize effective doses within a reduced exposure timeframe. [ABSTRACT FROM AUTHOR]

Research background. Anthocyanin pigments in mangosteen pericarp can serve as natural colourants; however, their stability is compromised by enzymatic browning caused by polyphenol oxidase (PPO). Thus, this study aims to investigate how hot water and steam blanching affect the PPO activity, phenolic profile and antioxidant properties of mangosteen pericarp. Experimental approach. Fresh mangosteen pericarp was blanched in hot water or steam at 100 °C for 0, 30, 60, 90 and 120 s and the residual PPO activity, total phenolic content (TPC), total anthocyanins, antioxidant activity, browning index and colour properties were evaluated. Additionally, the phenolic compounds were identified using liquid chromatography-mass spectrometry (LC-MS). Results and conclusions. Zero-order reaction kinetics (R2>0.800) showed that residual PPO activity was significantly (p<0.05) reduced in both blanched and steamed mangosteen pericarp. As expected, PPO was inactivated more rapidly in hot water (t1/2=59.0 s) than in steam blanching (t1/2=121.1 s). However, the principal component analysis (PCA) showed that steam blanching for 90 s was the most efficient method, preserving the highest levels of antioxidant capacity, expressed as Trolox equivalents (TE; 9135 µmol/g), Fe(III)-reducing power, expressed as TE, (9729 µmol/g), total anthocyanins (3.03 mg/g), and TPC, expressed as gallic acid equivalents (1057 mg/g). Overall, steam blanching for 90 s was the most efficient method because it best preserved the phenolic compounds and is also a cost-effective method compared to hot water, which needs to be replaced after a few applications. Novelty and scientific contribution. This is the first study to report the effects of blanching on the anthocyanins mainly present in mangosteen pericarp, in particular cyanidin-3-O-sophoroside (C3S) and cyanidin-3-O-glucoside (C3G), using high-performance liquid chromatography (HPLC) and LC-MS. This study makes a significant scientific contribution to the food industry by providing suitable blanching methods to preserve the quality of bioactive compounds, especially anthocyanins in mangosteen pericarp, which can be used as a natural colourant. [ABSTRACT FROM AUTHOR]

This study investigated the effect of exogenous plant growth regulators (PGR), namely jasmonic acid (JA) and methyl jasmonate (MeJA), on the physicochemical properties of flesh and peels of red-fleshed dragon fruit (Hylocereus polyrhizus). The fruit was sprayed with 100 and 1,000 ppm of JA and MeJA at 15 and 22 days of anthesis and harvested after 35 days. Then, the flesh and peels were analyzed for total soluble solids (TSS), total betacyanins, betanin, total phenolics (TP), total flavonoids (TF), and color characteristics. The fruit peels contained significantly higher (p<0.05) TP and antioxidant activities compared to flesh. No significant difference was detected between the variables in the peels, except for significantly higher (p<0.05) of total betacyanins (~295.6 and ~299.9 mg/100 g) and TP (~614.1 and 566.1 mg GAE/100 g) were recorded in control and 100 ppm MeJA, respectively. In the flesh, 1,000 ppm MeJA-treated fruit possessed the highest total betacyanins (~139.2 mg/100 g), betanin (~356.0 mg/g), TP (~244.9 mg GAE/100 g), TF (~329.0 mg CE/100 g), Trolox equivalent antioxidant capacity (TEAC) (63.2 µmol TE/g) and reducing power (~21.5 µmol TE/g). Overall, 1,000 ppm MeJA was more effective in enhancing the accumulation of bioactive compounds and antioxidant activities in the flesh of red-fleshed dragon fruit compared to other PGR treatments. [ABSTRACT FROM AUTHOR]

Robusta coffee is one of Malaysia’s most planted species due to its ability to adapt to the local climate. Nonetheless, the coffee species was perceived as having lower quality and economic value due to bitterness and astringency. It is widely believed that higher caffeine and chlorogenic acid contents in Robusta coffee beans contributed to the unfavourable bitter and astringent flavour. Hence, the present study intends to evaluate the effect of spontaneous wet fermentation (SWF) of locally grown Robusta (Coffea canephora L.) coffee towards the microbiological properties, phytochemical constituents, in particular caffeine and chlorogenic acids (CGA), total phenolic content (TPC), and antioxidant properties. The SWF of green Robusta coffee beans from University Agricultural Park (UAP), Universiti Putra Malaysia, Serdang, Selangor, took place at ambient temperatures between 25 to 28°C, and the pH decreased from 5.2 to 3.64 over five days of fermentation. The total plate count, lactic acid bacteria (LAB) and yeasts were significantly increased to approximately 7 Log10 CFU/g. The SWF has reduced caffeine content by 35%, while the CGA has decreased by roughly 20%. The SWF also led to an increase in TPC of approximately 31.5% and an increase in antioxidant activity of approximately 60%. [ABSTRACT FROM AUTHOR]

Spontaneous fermentation is becoming ever more elusive because of vast natural microbiota profiles that affect geographical region, climate, and applications of agrichemicals. This study aimed to identify the physicochemical and sensory properties of local planted (Serdang, Malaysia) Robusta (Coffea canephora L.) coffee beans after undergoing different spontaneous wet fermentation (SWF) periods i.e., 0 days as control, 3 days, and 5 days. The hardness decreased significantly (p < 0.05) by 80 to 90% in roasted fermented roasted Robusta coffee (FRRC) beans. The carbohydrate content was significantly higher (p < 0.05) at 9.4%, but protein and crude fibers were significantly (p < 0.05) lower at 31% and 9.7%, respectively. While the FRRC brew displayed deeper lightness (L*31.983), the FRRC powder displayed lighter lightness (L*49.553). The total soluble solid (TSS) was around 21% higher in FRRC and the water solubility index (WSI) had equivalent outcomes at about 8% higher in FRRC. Rheological analysis showed that the coffee fluid exhibited a shear-thickening property with fluid elastic components greater than viscosity. FRRC beans received higher ratings (score > 6) than non-FRRC beans (score between 5 and 6) in the consumer sensory evaluations. [ABSTRACT FROM AUTHOR]

Propolis is a good source for flavonoids, however, their recovery is challenging, as it is a waxy material. This study investigated edible oils virgin coconut oil (VCO), corn oil (CO), and ghee (G) as co-extractants for the supercritical carbon dioxide (scCO2) extraction of flavonoids from the propolis. The extraction of flavonoids using 20% VCO as co-extractant with scCO2 (25 g/min) for 210 min at 150 bar and 50°C was found to be the most appropriate, yielding a total flavonoid content (TFC) of 11.7 mg/g and 25% TFC recovery. At a higher temperature (60°C) and pressure (250 bar and 350 bar), the propolis became softer and compressed causing the extractions to retrograde. The extraction curves correlated to the diffusion model with 1.6% (AARD). The matrix diffusivities increased from 4.7 × 10-11 m2/s (scCO2) to 6.9 × 10-11-21.4 × 10-11 m2/s upon the addition of edible oils. Thus, edible oils could be used with scCO2 to improve the flavonoid extraction from propolis. [ABSTRACT FROM AUTHOR]