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Sulfur dioxide (SO2) are a category of chemical compounds widely used as additives in food industry. So far, the use of SO2 in fruit and vegetable industry has been indispensable although its safety concerns have been controversial. This article comprehensively reviews the chemical interactions of SO2 with the components of fruit and vegetable products, elaborates its mechanism of antimicrobial, anti-browning, and antioxidation, discusses its roles in regulation of sulfur metabolism, reactive oxygen species (ROS)/redox, resistance induction, and quality maintenance in fruits and vegetables, summarizes the application technology of SO2 and its safety in human (absorption, metabolism, toxicity, regulation), and emphasizes the intrinsic metabolism of SO2 and its consequences for the postharvest physiology and safety of fresh fruits and vegetables. In order to fully understand the benefits and risks of SO2, more research is needed to evaluate the molecular mechanisms of SO2 metabolism in the cells and tissues of fruits and vegetables, and to uncover the interaction mechanisms between SO2 and the components of fruits and vegetables as well as the efficacy and safety of bound SO2. This review has important guiding significance for adjusting an applicable definition of maximum residue limit of SO2 in food. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the application of hot water treatment to tomato fruits (Solanum lycopersicum cv. TA234) genetically modified with silencing of the TomloxB gene. Unmodified and genetically modified tomato fruits were immersed in water at 40°C for 10, 20 and 30 seconds. Subsequently, fruits were stored at 25°C for 18 days. Physiology was assessed and electrolyte leakage, lipoxygenase and polygalacturonase activities were monitored. Treatment applied to the genetically modified tomatoes at 40°C for 30 seconds, resulted in slower ripening, decreased metabolic activity and maintained the attributes in optimal conditions for longer time, increased the postharvest life of the genetically modified tomatoes until 18 days. Lipoxygenase and polygalacturonase activities were partially inhibited. [ABSTRACT FROM AUTHOR]

Applications of biotechnological tools in food preservation have shown promising results in minimizing food spoilage. Design and development of highly efficient food preservatives are one of the key success factors in this application field. However, due to the inherent shortcomings of the bulk forms of such preservatives, research was in progress to find suitable alternatives to replace conventional modalities. The intervention of nanotechnology has made this approach feasible in almost every aspect of food preservation. This interface domain of nanobiotechnology has been very well explored in the last few decades and vast literature has been reported. Researchers have developed efficient nanopreservatives (NPRs) for diverse applications. However, the literature available on nano-based food preservation is not inclusive of molecular perspectives involved in food preservation. There is a large knowledge gap in the interface domain concerning the physics of intermolecular and interfacial forces and nanotechnology which play decisive roles in designing edible coatings (ECs). There is an urgent need for identifying the nano and molecular level contributing factors for developing efficient NPRs. Moreover, it is imperative to understand the possible health impact of NPRs in public interest and concern. This review revisits the fundamental aspects of food preservation and navigates through the applicability, safety, molecular aspects and future direction of NPRs. [ABSTRACT FROM AUTHOR]

Super-atmospheric O2has been shown to affect respiration rate (RR), but no model describing its effect on RR for pomegranate arils has been reported. This study investigated the effects of four different gas compositions (5 kPa O2, 10 kPa CO2and 85 kPa N2; 10 kPa O2, 5 kPa CO2and 85 kPa N2; 70 kPa O2, 10 kPa CO2and 20 kPa N2; and air) on RR of pomegranate arils (cv. Wonderful) stored at 5°C. Michaelis–Menten enzyme kinetics models were used to investigate the effect of CO2inhibition on O2consumption rate. Respiratory quotient was used to determine fermentation threshold. The O2consumption rate increased from 0.87 to 2.81 mL/kg h, with increase in O2concentration from 5 kPa to 70 kPa. All enzyme kinetics model parameters adequately described the influence of gas concentration on aril RR with correlation coefficient (R2adj = 81–91%). [ABSTRACT FROM AUTHOR]

Several of the conifer species are increasingly adopted as Christmas trees worldwide. These species have become integral parts of the horticultural economies of North American and European countries. Postharvest characteristics such as needle abscission/retention, color, fragrance and rehydration abilities vary with species and these complex physiological traits are strongly modulated by hormonal and environmental factors. A large body of research indicates that prevalence of low temperature before harvest evokes cold acclimation responses that involve an increase in complex sugar concentrations, alterations in membrane structures and enhancements in scavenging abilities promoting postharvest needle retention. Adverse postharvest environmental factors, for example, high temperature and vapor pressure deficit are found to increase water stress, cause dehydration and accelerate needle abscission and/or discoloration. Postharvest water stress/cellular dehydration is one of the fundamental biophysical signals that triggers a cascade of hormonal changes, leading to needle abscission. Abscissic acid levels increase during cold acclimation as well as prior to abscission indicating a complicated and paradoxical role in abscission. Ethylene levels increase before abscission and are well proven to instigate the needle fall. Concentrations of cytokinins, auxins and polyamines decline postharvest. However, their interactive roles with other phytohormones orchestrating the abscission process still remain elusive. This review presents and discusses our current knowledge of the physiological aspects of pre-and postharvest environmental factors on needle abscission. [ABSTRACT FROM PUBLISHER]

The effects of humic substances (AgriPlus, Humi-Zyme, and Humic Acid 6%) and nitrogen (N) on growth, yield, quality, and leaf minerals in apple ( Malus domestica Borkh.) were studied during 1997–2000. Trees receiving medium or high N tended to be larger than trees with other treatments in 2000. Trees receiving AgriPlus with high N had higher yield than untreated control trees in 1998. Trees receiving medium N had larger fruits than control trees. Fruits of trees receiving high N (alone) had less red color than the control. Soluble solids concentrations (SSC) in fruits of all treatments were higher than those of the control at harvest in 1999. Fruit from the untreated control and low Humi-Zyme tended to be firmer than that from other treatments. The untreated control and low Humi-Zyme trees had lower leaf N and manganese (Mn), but higher leaf potassium (K) than trees under most other treatments. Leaf iron (Fe) in trees receiving medium Humi-Zyme was higher than that in the untreated control in two years. AgriPlus-treated trees showed higher water retention in the root zone. [ABSTRACT FROM AUTHOR]

The topic of food safety in the U.S. frequently is the lead story in the news media and continues to be an important issue for biological scientists of all disciplines. The emotional and sensational aspects of food safety often cloud the facts as reported by journalists. Because we increasingly depend on foreign countries for our food supply, and because of the commonly held belief in our society that foreign suppliers are not required to meet the safety criteria of U.S. regulatory agencies, it is important for agriculturalists with international expertise to offer objective views on the topic of food safety. This report contains the observations and views of one such scientist. [ABSTRACT FROM AUTHOR]