Controlled Atmosphere Storage Alleviates Chilling Injury and Ameliorates Aroma Quality by Enhancing Reactive Oxygen Species Scavenging Ability in Peach Fruit

In order to explore the effect of controlled atmosphere (CA) storage on alleviating chilling injury (CI) in peach fruit and the possible underlying mechanism, the effect of CA treatment (5% O2 + 10% CO2) on internal browning index (IB), firmness, ethylene release rate, reactive oxygen species (ROS) content, malondialdehyde (MDA) content, compounds and key enzyme activities related to the ascorbic acid-glutathione (AsA-GSH) cycle and volatile contents in yellow-fleshed peach fruit (cv. Jinxiu) during low temperature ((0 ± 2) ℃) storage and shelf (20 ℃, 3 d) was investigated. The results showed that CA alleviated CI significantly relative to the control group; on the third day of the shelf life after 30-day cold storage (30dS3), IB was lower than 10%, fruit firmness decreased to below 10 N, and ethylene release rate was 1.7-fold as high as in the control. During the late period of cold storage, the contents of total ROS, MDA, and hydrogen peroxide (H2O2) were significantly lower and scavenging capacities against 1,1-diphenyl-lpicrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation free radicals were significantly higher in the CA-treated fruit than the control group (P < 0.05 or P < 0.01). Meanwhile, in the CA-treated peach fruit, the activity of superoxide dismutase (SOD) was increased by 36% on 30dS3, while the activities of AsA-GSH cycle-related key enzymes such as ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR) and monodehydroascorbate reductase (MDHAR) were enhanced, and the conversion of reduced ascorbic acid to dehydroascorbic acid was significantly inhibited. Moreover, CA treatment accumulated higher amounts of C6 alcohols, esters, and lactones compared with the control group at the end of the shelf life; on 30dS3, the contents of γ-hexalactone, γ-decalactone, and δ-decalactone were increased by 3.0, 2.6 and 5.0 folds compared with the control group, respectively. In addition, higher contents of sucrose and sorbitol and lower contents of glucose and fructose were observed in the CA-treated fruit. Therefore, CA treatment (5% O2 + 10% CO2) can alleviate CI and maintain aroma quality by activating the AsA-GSH cycle and SOD, and enhancing ROS scavenging capacity in peach fruit

Effects of slightly acidic electrolyzed water on the quality and antioxidant capacity of fresh red waxy corn during postharvest cold storage

Fresh red waxy corn is consumed worldwide because of its unique flavor and rich nutrients, but it is susceptible to deterioration with a short shelf life. This study explored the effect of slightly acidic electrolyzed water (SAEW) treatment on the quality and antioxidant capacity of fresh red waxy corn during postharvest cold storage up to 40 d. The SAEW treatment exhibited lower weight loss, softer firmness, and higher total soluble solids (TSS) and moisture content than the control group. Correspondingly, the SAEW maintained the microstructure of endosperm cell wall and starch granules of fresh red waxy corn kernels well, contributing to good sensory quality. Furthermore, SAEW effectively reduced the accumulation of H2O2 content, elevated the O2−· scavenging ability, maintained higher CAT and APX activities, and decreased the decline of the flavonoids and anthocyanin during the storage. These results revealed that the SAEW treatment could be a promising preservation method to maintain higher-quality attributes and the antioxidant capacity of fresh red waxy corn during postharvest cold storage

Frozen-Phase High-Pressure Destruction Kinetics of Escherichia coli as Influenced by Application Mode, Substrate, and Enrichment Medium

The synergistic effect of frozen-phase high pressure (HP) on the inactivation of E. coli ATCC 25922 cultures in suspension medium, Chinese bayberry juice (pH 3.0), and carrot juice (pH 6.5) was evaluated. The survivor count of E. coli remained at 3.36 log CFU/mL on a nonselective brain heart infusion (BHIA) medium, while no survivor was detected on a selective violet red bile agar (VRBA) medium after a 5 min hold pressure at 250 MPa in a frozen culture suspension. BHIA was suitable for safe testing of the injured E coli cells after HP treatment in frozen state. Frozen Chinese bayberry juice showed higher sensitivity to HP treatment for its matrix property with high sterilizing efficiency at 170 MPa. Two pulses exhibited a significant inactivation effect in frozen samples compared with one pulse, especially for the Chinese bayberry juice with different pressure levels. The destruction kinetics of HP pulse mode followed the first-order rate kinetics with a Zp value of 267 MPa in frozen carrot juice. Our results evaluated the influenced factors of frozen HP destruction effects, including the medium, substrate, and application mode. The frozen HP destruction kinetics of pulses afford us better understanding of the technology application in the food industry

Extraction, Structural Characterization, Biological Functions, and Application of Rice Bran Polysaccharides: A Review

Rice bran is a &ldquo;treasure house of natural nutrition&rdquo;. Even so, utilization of rice bran is often ignored, and this has resulted in the wastage of nutrients. Polysaccharides are one of the active substances in rice bran that have gained widespread attention for their antioxidant, antitumor, immune-enhancing, antibacterial, and hypoglycemic properties. This review summarizes the extraction methods, structural characterization, bioactivity, and application of rice bran polysaccharides that have been developed and studied in recent years, laying a foundation for its development into foods and medicines. In addition, we also discuss the prospects for future research on rice bran polysaccharides

Changes of Sensory Quality, Flavor-Related Metabolites and Gene Expression in Peach Fruit Treated by Controlled Atmosphere (CA) under Cold Storage

Controlled atmosphere (CA) has been used to alleviate chilling injury (CI) of horticultural crops caused by cold storage. However, the effects of CA treatment on peach fruit sensory quality and flavor-related chemicals suffering from CI remain largely unknown. Here, we stored peach fruit under CA with 5% O2 and 10% CO2 at 0 °C up to 28 d followed by a subsequent 3 d shelf-life at 20 °C (28S3). CA significantly reduced flesh browning and improved sensory quality at 28S3. Though total volatiles declined during extended cold storage, CA accumulated higher content of volatile esters and lactones than control at 28S3. A total of 14 volatiles were positively correlated with consumer acceptability, mainly including three C6 compounds, three esters and four lactones derived from the fatty acid lipoxygenase (LOX) pathway. Correspondingly, the expression levels of genes including PpLOX1, hyperoxide lyase PpHPL1 and alcohol acyltransferase PpAAT1 were positively correlated with the change of esters and lactones. CA elevated the sucrose content and the degree of fatty acids unsaturation under cold storage, which gave us clues to clarify the mechanism of resistance to cold stress. The results suggested that CA treatment improved sensory quality by alleviating CI of peach fruits under cold storage

Recent Developments in Molecular Characterization, Bioactivity, and Application of Arabinoxylans from Different Sources

Arabinoxylan (AX) is a polysaccharide composed of arabinose, xylose, and a small number of other carbohydrates. AX comes from a wide range of sources, and its physicochemical properties and physiological functions are closely related to its molecular characterization, such as branched chains, relative molecular masses, and substituents. In addition, AX also has antioxidant, hypoglycemic, antitumor, and proliferative abilities for intestinal probiotic flora, among other biological activities. AXs of various origins have different molecular characterizations in terms of molecular weight, degree of branching, and structure, with varying structures leading to diverse effects of the biological activity of AX. Therefore, this report describes the physical properties, biological activities, and applications of AX in diverse plants, aiming to provide a theoretical basis for future research on AX as well as provide more options for crop breeding

A comparison of chemical composition, bioactive components and hypoglycemic activity of Stigma maydis obtained from different growing times

AbstractStigma maydis (SM) possesses remarkable nutritional value due to the presence of health-protective chemical constituents in it. Despite its commercial uses, there is a lack of information on changes in the nutritional profile of SM during Shenke 601 waxy corn development by following four different maturity stages (silking stage; blister stage; milky stage; dough stage). In this study, the ideal times for the development of seven active compounds (polysaccharides, saponin, rutin, luteolin, quercetin, kaempferol and chlorogenic acid) were at the silking stage. The total flavonoid and total phenol content increased as the SM matured. Except for the above-mentioned active compounds, the content of major nutritional components of dough stage was higher than that of three other stages. The extract of Stigma maydis exhibited good α-amylase, α-glucosidase and pancreatic lipase inhibition activities. The ethanolic SM extracts showed better inhibitory effects than aqueous SM extracts with a dose–effect relationship. The hypoglycemic activity of ethanolic extract was higher than that of aqueous extract at each stage. This provided an important basis for the application of SM