To study the impacts of thermosonication (TS), the spinach juice treated with TS (200 W, 400 W, and 600 W, 30 kHz, at 60 ± 1 °C for 20 mint) were investigated for bioactive compounds, antioxidant activities, color properties, particle size, rheological behavior, suspension stability, enzymatic and microbial loads. As a result, TS processing significantly improved the bioactive compounds (total flavonols, total flavonoids, total phenolic, carotenoids, chlorophyll, and anthocyanins), antioxidant activities (DPPH and FRAP assay) in spinach juice. Also, TS treatments had higher b*,L*, hue angle (h0), and chroma (C) values, while minimuma* value as compared to untreated and pasteurized samples. TS processing significantly reduced the particle size, improved the suspension stability and rheological properties (shear stress, apparent viscosity, and shear rate) of spinach juice as compared to the untreated and pasteurized sample. TS plays a synergistic part in microbial reduction and gained maximum microbial safety. Moreover, TS treatments inactivated the polyphenol oxidase and peroxidase from 0.97 and 0.034 Abs min-1 (untreated) to 0.31 and 0.018 Abs min-1, respectively. The spinach juice sample treated at a high intensity (600 W, 30 kHz, at 60 ± 1 °C for 20 mint, TS3) exhibited complete inactivation of microbial loads (<1 log CFU/ml), the highest reduction in enzymatic activities, better suspension stability, color properties, and highest bioactive compounds. Collectively, the verdicts proposed that TS processing could be a worthwhile option to pasteurize the spinach juice to enhance the overall quality.

Plant-associated microbes are critical for plant growth and survival under natural environmental conditions. To date, most plant microbiome studies involving high-throughput amplicon sequencing have focused on the relative abundance of microbial taxa. However, this technique does not assess the total microbial load and the abundance of individual microbes relative to the amount of host plant tissues. Here, we report the development of a host-associated quantitative abundance profiling (HA-QAP) method that can accurately examine total microbial load and colonization of individual root microbiome members relative to host plants by the copy-number ratio of microbial marker gene to plant genome. We validate the HA-QAP method using mock experiments, perturbation experiments, and metagenomic sequencing. The HA-QAP method eliminates the generation of spurious outputs in the classical method based on microbial relative abundance, and reveals the load of root microbiome to host plants. Using the HA-QAP method, we found that the copy-number ratios of microbial marker genes to plant genome range from 1.07 to 6.61 for bacterial 16S rRNA genes and from 0.40 to 2.26 for fungal internal transcribed spacers in the root microbiome samples from healthy rice and wheat. Furthermore, using HA-QAP we found that an increase in total microbial load represents a key feature of changes in root microbiome of rice plants exposed to drought stress and of wheat plants with root rot disease, which significantly influences patterns of differential taxa and species interaction networks. Given its accuracy and technical feasibility, HA-QAP would facilitate our understanding of genuine interactions between root microbiome and plants.

Degradation of meat quality has always been a burning issue in fish preservation. To maintain the quality, a novel combination of chlorogenic acid (CGA) and chitosan (CS) coating was applied to snakehead fish fillets. Fish fillets were soaked into 2% chitosan (2CS), 0.2% CGA in 2% chitosan (0.2CGA/2CS), 0.5% CGA in 2% chitosan (0.5CGA/2CS), or 1.0% CGA in 2% chitosan (1.0CGA/2CS) solution; and then, coated samples were vacuum-packaged and stored at 2 ± 0.5°C. pH values, color values, microbial loads, hardness, sensory qualities, and oxidization of lipids and proteins of stored fish fillets were investigated for 5 months. Antimicrobial activity was found to be nonsignificant (p ≤ .05) among different coated fish fillets, while color, antioxidant, and pH values were significantly (p ≤ .05) different. Lipid oxidation and protein oxidation were found to be inhibited in 2CS-, 0.5CGA/2CS- and 1.0CGA/2CS-coated fish fillet. All CGA/CS coating delayed increase in pH (p ≤ .05) and resulted brown color. However, only CS coating resulted in higher sensory scores (p ≤ .05) and controlled browning. Considering antioxidant properties and other quality parameters, CGA/CS coating might be applied commercially in fish preservation.

BACKGROUND: In this study, we evaluated the combined effect of cinnamon essential oil (CEO) microemulsions, and a temperature buffering package using phase-change material (PCM) microcapsules on the physicochemical property, lipid oxidation, and bacterial load of traditional Chinese pork balls (shi zi tou) during temperature fluctuation storage for 9 days.
RESULTS: Transmission electron microscope characterization revealed that n-tetradecane microcapsules possessed a core-shell spherical shape with a size ranging from 300 to 600 nm. The use of n-tetradecane microcapsule packaging was found to maintain cold storage temperature efficiently. After 9 days of storage, the combination of CEO microemulsions with n-tetradecane microcapsules did not lead to changes in the color parameters of pork balls. At day 9, n-tetradecane microcapsules, used alone or in combination with CEO microemulsions, showed lower thiobarbituric acid reactive substances (TBARS) values than the control group, while their combination exhibited the lowest pH and 1,1-diphenyl-2-picrylhydrazyl (DPPH) values. Furthermore, the combination treatment retarded the growth of total plate count, lactic acid bacteria, Enterobacteriaceae, and Staphylococcus spp. after 4 and 9 days.
CONCLUSIONS: The combinations of CEO microemulsions and PCM microcapsules could extend the shelf-life of cooked pork products, suggesting a feasible strategy for meat preservation. © 2020 Society of Chemical Industry.

A novel nano-silicon oxides (SiOx)/chitosan complex film was prepared using ultrasonic assistant in the process of dissolving chitosan and silicon oxides (SiOx), and characterized by transmission electron microscopy. Its effect on quality preservation of tomatoes (Solanum lycopersicum L. cv. Zheza 205) was investigated under ambient temperature. The results revealed that the nano-SiOx/chitosan complex (NSCC) film retarded weight loss and softness, delayed the titratable acids and total soluble solids loss, and thus markedly extended shelf life of green tomatoes. The antimicrobial activity of tomatoes coated with NSCC film was also recorded higher compared to chitosan (Ch) films and control. In addition, the NSCC film-coated tomatoes prevent the increase of malondialdehyde content and total polyphenol content. Moreover, the peroxidase activity, phenylalanine ammonia-lyase activity, and polyphenoloxidase activity of tomatoes coated with NSCC film were found lower than that in other treatments. These data indicated that the beneficial effects of nano-SiOx/chitosan complex coating on postharvest quality were possibly associated with the lower rate of O2/CO2 transmission coefficient, limiting food-borne pathogenic bacterial growth, higher antioxidant activities, and also higher reactive oxygen species (ROS) scavenging and anti-browning activities of related enzymes in the tomatoes. Further, the results of the study could be used to successfully develop a novel nano-SiOx/chitosan complex film for improving the postharvested quality of tomatoes and thus effectively utilized by the food packaging industry.

In this study, thermosonication was used as a combined treatment of raw goat milk (RGM) using pasteurization (72 °C for 15 s) and ultrasound treatments (20 kHz at the power variance of 150 W, 200 W, 300 W and 400 W for 10 min). Investigation on the impact of the microbial load, protein content, protein aggregation, the particle size of fat and casein micelles, pH, viscosity, turbidity, color, and soluble calcium and phosphorus contents were carried out, whiles RGM and PGM served as the control. Our results revealed that at 400 W, that thermosonication resulted in a significant reduction (α = 0.05) in the microbial load of the samples to less than 2.3 log cfu/mL in comparison to those of RGM and pasteurized goat milk (PGM) at 5.94 log cfu/mL and 4.76 log cfu/mL respectively. In RGM, the fat size (3.5 µm) decreased to 0.4 µm at 300 W; while those of casein micelles also decreased from 406 to 256.4 nm at 400 W. However, no significant effect was observed in the color and soluble calcium and phosphorus contents of all samples. The effect on the microbial load and fat homogenization would promote thermosonication process in the dairy industry.

Fresh coriander leaves are highly perishable in nature and their sensory quality and nutritional value decreases without proper processing or preservation. In the present study, three aqueous solutions of sodium hypochlorite (SH, 100 mg/L), chlorine dioxide (CD, 10 mg/L), and sodium butyl p-hydroxybenzoate (SBPH, 12 mg/L), and tap water, were used to treat fresh coriander for 15 min. The treated samples were packed in PVC boxes with ambient air under packaged under passive modified atmosphere packaging conditions and stored at 4 °C for 10 days. Effects of washing treatments on color, total chlorophyll contents, ascorbic acid contents, total contents of phenolic compounds, and total aerobic bacterial counts (APC) were investigated. CD treatment has the least detrimental effects on color, total chlorophyll contents and ascorbic acid contents of fresh coriander, followed by SH treatment. In addition, CD treatment showed a greater reduction in APC and maintained the microbial load at lower levels than other treatments during the 10-day storage period.