No abstract

No abstract

Using corn starch (CS) and κ-carrageenan(κC) as the raw material and active composite, respectively, films containing different concentrations of ethanol extract of onion skin were prepared. The effects of different concentrations of ethanol extract of onion skin (EEOS) on the physicochemical properties, as well as the antioxidant and antibacterial properties, of CS/κC films were also discussed. The addition of ethanol extract of onion skin inhibited the recrystallization of starch molecules in the composite films. It affected the microstructure of the composite films. The color of the composite films was deepened, the brightness was reduced, and the opacity was increased. Water vapor permeability increased, tensile strength decreased, and elongation at the break increased. The glass-transition temperature decreased. The clearance of DPPH radicals and ABTS cation radicals increased. Moreover, when the concentration of EEOS was 3%, the antioxidant effect of the films on oil was greatly improved and could effectively inhibit Staphylococcus aureus and Escherichia coli. The above results showed that adding ethanol extract of onion skin improved the physicochemical properties and biological activities of the CS/κC composite films, so CS/κC/EEOS composite films can be used as an active packaging material to extend food shelf-life. These results can provide a theoretical basis for the production and application of corn starch/κ-carrageenan/ethanol extract of onion skin composite films.

In this study, the effects of ethanolic extract from onion skin (EEOS) on the storage quality of refrigerated beef patties were studied. EEOS concentrations of 0.00%, 0.01%, 0.05%, and 0.10% were added to beef patties. These beef patties were stored at 4 °C for 12 days and compared with 0.05 V C treatment group. At the end of storage, compared to control, 0.1% EEOS effectively reduced the contents of metmyoglobin (MetMb) (P < 0.05) and thiobarbituric acid reactants (TBARS) (P < 0.05) in beef patties by 30.89% and 44.72%, respectively. On day 12, the carbonyl contents in 0.1% EEOS treatment increased only 3.3 times, lower than control and V C treatment (4.5 and 4.1 times). Microbial contamination was significantly inhibited (P < 0.05). The antioxidant and antibacterial effects of EEOS were the main reasons for the improvement of pH and a* stability of beef patties. However, the addition of EEOS had no significant effect on cooking loss and texture properties except hardness and springiness. Overall, 0.1% EEOS had a positive effect on the sensory characteristics and storage quality of beef patties and could prolong the storage life of beef patties to 9 days. This showed that EEOS as a natural additive has great potential for beef storage and preservation.

Accumulating evidence has linked benzo(α)pyrene (BαP) exposure to carcinogenesis with severe damages to reproductive, hematopoietic, hepatic, and renal tissues. Ginger (Zingiber officinale Roscoe) rhizome consumed worldwide as a spice and herbal medicine, exhibits a variety of health benefits including antioxidant, anti-inflammatory, and anti-cancer activities. In the present work, the efficacy of three ginger compounds namely 6-gingerol, zingerone, and curcumin against BαP-induced toxicity in mice was investigated. Kunming Swiss albino male mice were orally gavage with curcumin, 6-gingerol, or zingerone (all at a dose of 100 mg/kg body weight) for two weeks before intraperitoneal injection with benzo(α)pyrene (BαP) at 20 mg/kg body weight. The effect of these ginger compounds on antioxidant and xenobiotic-metabolising enzymes in vivo was investigated. Results showed that pre-treatment with curcumin, 6-gingerol, or zingerone significantly (p < 0.05) increased catalase (CAT) and glutathione peroxidase (GPx) activities in serum and liver of mice, upregulated activities of phase II enzymes (quinone reductase (QR) and glutathione-S-transferase (GST)), and their protein and mRNA levels in liver of mice; but reduced levels of activities, protein, and mRNA of phase I enzymes (CYP1A1 and CYP1A2) as compared to those of BαP-only treatment. Furthermore, these compounds significantly (p < 0.05) stimulated nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression, whilst curcumin suppressed the expression of Kelch-like ECH-associated protein 1 (Keap1) in liver. These results could contribute to our understanding of the potential beneficial effects of consuming ginger as food and/or dietary supplement.