Characterization of Natural Anthocyanin Indicator Based on Cellulose Bio-Composite Film for Monitoring the Freshness of Chicken Tenderloin.

Intelligent packaging with indicators that provide information about the quality of food products can inform the consumer regarding food safety and reduce food waste. A solid material for a pH-responsive indicator was developed from hydroxypropyl methylcellulose (HPMC) composited with microcrystalline cellulose (MCC). MCC at 5%, 10%, 20%, and 30% w/w was introduced into the HPMC matrix and the physical, barrier, thermal, and optical properties of the HPMC/MCC bio-composite (HMB) films were analyzed. At 5, 10, and 20% MCC, improved mechanical, transparency, and barrier properties were observed, where HMB with 20% of MCC (H20MB) showed the best performance. Therefore, H20MB was selected as the biodegradable solid material for fabricating Roselle anthocyanins (RA) pH sensing indicators. The performance of the RA-H20MB indicator was evaluated by monitoring its response to ammonia vapor and tracking freshness status of chicken tenderloin. The RA-H20MB showed a clear color change with respect to ammonia exposure and quality change of chicken tenderloin; the color changed from red to magenta, purple and green, respectively. These results indicated that RA-H20MB can be used as a biodegradable pH sensing indicator to determine food quality and freshness.

Effect of moisture-controlled packaging treatment with acid-modified expanded vermiculite-calcium chloride on the quality of fresh mushrooms (Agaricus bisporus) during low-temperature storage.

BACKGROUND: Fresh mushrooms (Agaricus bisporus) are highly perishable and easily lose quality during storage. The packaging system can retard the deterioration of fresh mushrooms. However, water vapor transmission rates of commodity plastic films are lower than the transpiration rate of mushrooms, resulting in increased moisture condensation in the package and perishability of mushrooms due to microbial growth. A possible solution for controlling the humidity level in the package is to use a hygroscopic material. Acid leaching can improve the chemical and physical properties of expanded vermiculite (EV). The aim of this study was to develop a novel hygroscopic agent from acidified expanded vermiculite (AEV) and calcium chloride (CaCl2 ) that has a high moisture absorption capacity and maintains a powdered form in the packaging system for fresh mushrooms. RESULTS: Our findings revealed that leaching EV with hydrochloric acid increased porosity and hydrophilicity. The combination of AEV:CaCl2 at 6:4 (w/w, AEV/CS40) showed the highest moisture adsorption capacity at 1.724 ± 0.03 g water per gram of material. Then, 1.55 g of AEV/CS40 was applied to the mushroom packaging and stored at 4 °C. The results indicated that AEV/CS40 could delay mushroom deterioration in terms of color change, firmness, pH, total soluble solids, and microbial growth. CONCLUSION: The study findings indicate that the alternative solid hygroscopic material obtained by combining AEV with CaCl2 has potential for use as a hygroscopic material for preserving the quality of white button mushrooms. © 2021 Society of Chemical Industry.

Exogenous Melatonin Reduces Lignification and Retains Quality of Green Asparagus (Asparagus officinalis L.).

Asparagus (Asparagus officinalis L.) is highly perishable because of its high respiration rate, which continues after harvesting and leads to weight loss, increased hardness, color change, and limited shelf life. Melatonin is an indoleamine that plays an important role in abiotic stress. This study was designed to investigate the effects of melatonin on the quality attributes of green asparagus during cold storage. Green asparagus was soaked in a melatonin solution (50, 100, and 200 µM) for 30 min and then stored at 4 °C under 90% relative humidity for 25 days. The results indicated that melatonin treatment delayed the post-harvest senescence of asparagus and maintained high chlorophyll and vitamin C levels. Melatonin treatment hindered phenylalanine ammonia-lyase and peroxidase activities and reduced lignin content, thereby delaying the increase in firmness. Moreover, melatonin treatment enhanced catalase and superoxide dismutase activities, leading to reduced hydrogen peroxide content. These results indicate that melatonin treatment can be used to maintain the post-harvest quality and prolong the shelf life of green asparagus.

Enhancing gamma-aminobutyric acid content in germinated brown rice by repeated treatment of soaking and incubation.

Gamma-aminobutyric acid (GABA), commonly produced by germination of brown rice grain, is a free amino acid which could help relieving or preventing non-communicable diseases in human. Several research works have been conducted on GABA production from germinated brown rice. However, the yielded GABA (10.1-69.2 mg/100 g germinated brown rice) was comparatively low; thus the amount was insufficient to be used as active ingredients in functional foods. The objective of this study was to explore alternative methods in order to gain higher yield of GABA. A new process of repeated soaking (in tap water at 35 °C, 3 h) and incubation (at 37 °C, 21 h) during germination was developed. The amount of GABA produced was highest at 116.88 ± 9.24 mg/100 g germinated brown rice (dry basis). However, an unpleasant odour was generated by some microorganisms during long germination. Lactic acid was applied at soaking step to overcome this problem; whereby 0.5% lactic acid solution (vol./vol.) could effectively control the microorganisms without impairing GABA producing ability and sensory qualities.