Effects of active gelatin coated with henna (L. inermis) extract on beef meat quality during chilled storage

Effect of Gelatin Coating Enriched with Antioxidant Tomato By-Products on the Quality of Pork Meat

The use of edible biopolymers and natural additives obtained from food processing by-products is a sustainable strategy for food packaging applications. Gelatin is a biopolymer with great potential as a coating due to its low cost, high availability, and technological and functional properties. Among them, gelatin can be used as a carrier of bioactive compounds such as antioxidants, which can retard oxidation processes and thus extend the shelf-life of highly-perishable products. This study evaluated the effect of gelatin coating enriched with antioxidant tomato by-products hydrolysate (TBPH) on the quality of pork meat during cold storage. Results showed that TBPH obtained from Alcalase hydrolysis presented antioxidant activity with good stability against cooking. Additionally, chromatographic and mass spectrometry techniques, as well as in silico analysis, were used for the peptidomic characterisation of TBPH. The application of enriched gelatin coating on meat led to some physicochemical changes including increased weight loss and colour differences; however, the pH and water activity, which control meat spoilage, were maintained during storage. Moreover, coating prevented lipid oxidation of meat, and enriched-coated meat presented high antioxidant activity after cooking. These results suggest the positive role of gelatin coating enriched with TBPH in extending the shelf-life of meat during storage.

Characterization of moisture migration of beef during refrigeration storage by low-field NMR and its relationship to beef quality

BACKGROUND

In this study, low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) were used to investigated the moisture migration of beef during refrigeration storage, and its relationships to some physicochemical quality indicators were analyzed using partial least squares regression.

RESULTS

Three water components ascribed to bound water, immobilized water and free water in beef matrix were revealed by LF-NMR relaxation results. The transverse relaxation time and peak area of immobilized water declined as storage proceeded, as a result of disruption to the microstructure revealed by scanning electron microscope images. MRI images found obvious water migration of beef during refrigeration storage, and scanning electron microscopy images revealed that the integrity of the muscle fiber bundle was destroyed. In addition, increased storage time also led to increases in pH, total volatile basic nitrogen, TBARS (thiobarbituric acid reactive substances) value, weight loss, cooking loss and b* value, and to decreases in water holding capacity (WHC), L* and a* values, and textural properties.

CONCLUSION

The strong correlations between water migration and the physicochemical quality changes suggested the possibility of LF-NMR as a rapid and non-invasive method to evaluate beef quality. © 2019 Society of Chemical Industry.

Effect of red pepper (Zanthoxylum bungeanum Maxim.) leaf extract on volatile flavor compounds of salted silver carp

Chinese red pepper (Zanthoxylum bungeanum Maxim.) leaf (ZML) extract was added to salted silver carp. The effect of ZML extract on volatile compounds formation of both dorsal and ventral muscle of salted fish was investigated. Lipid oxidation of salted fish with ZML extract was alleviated with lower peroxide value (PV) and thiobarbituric acid reactive substance (TBARS) values than that of the control. Therefore, the contents of some volatile compounds formed mainly by oxidation such as benzene, methylbenzene, 1-octene-3-ol, hexanal, and methyl ketone, which attributed off-odor of salted fish, were reduced. Principal component analysis results showed that the first principal component (PC1) and the second principal component (PC2) explained 62% and 31% of total variance, respectively, and volatile compounds of the dorsal and ventral of control group differentiated from treatment group. These results showed that ZML extract can be a source of natural antioxidants and food additives for improving flavor of salted fish.

Shelf-life extension of whole shrimp using an active coating containing fish skin gelatin hydrolysates produced by a natural protease

This study was focused on shelf-life extension of whole shrimp (Penaeus merguiensis) using an active coating containing gelatin hydrolysates. Gelatin extracted from Scomberomorus commerson skin was hydrolyzed using actinidin extracted from kiwifruit. Some important physicochemical characteristics of fish skin gelatin including viscosity, gelling and melting points, and temperatures were examined. The whole shrimp was coated with four coating agents including fish skin gelatin (FG), commercial gelatin (CG), fish skin gelatin containing 1 mg/ml fish gelatin hydrolysates (FG + GH), and commercial bovine gelatin containing 1 mg/ml fish gelatin hydrolysates (CG + GH). Chemical, microbial, and sensorial properties of samples were monitored for 12 days at 4°C with 3-day intervals (0-12 days). The pH value of samples coated with FG + GH and CG + GH showed the lowest changes during 12 days of storage (1.68 ± 0.00 and 1.70 ± 0.09, respectively). The free fatty acid content (FFA), total volatile base nitrogen (TVB-N), lipid oxidation, and carbonyl content of samples coated with FG + GH and CG + GH were significantly lower than that of control, CG, and FG samples. The results of this study showed that the gelatin hydrolysates could be used as a preservative costing agent for whole shrimp.

The effects of gelatin-CMC films incorporated with chitin nanofiber and Trachyspermum ammi essential oil on the shelf life characteristics of refrigerated raw beef

The effects of gelatin-carboxymethyl cellulose (Gel-CMC) based films containing chitin nano fiber (CHNF) and Trachyspermum ammi essential oil (Ajowan), on the shelf life extension of the raw beef at refrigerated temperature (4 °C) over a 12-day period were evaluated. Ajowan essential oil (AJEO) and CHNF were added to the films at 0.24, 0.64 and 1% v/v; and 2 and 4 wt%, respectively. The microbiological (total viable count, psychrotrophic count, Pseudomonas spp., Staphylococcus aureus, lactic acid bacteria, molds and yeasts), the chemical (pH, thiobarbituric acid and total volatile basic nitrogen), color and sensory properties of the packaged samples were evaluated periodically. Bacteria grew the most quickly in the control samples, followed by those wrapped with the Gel-CMC films; The lowest microbial counts, the least change in the chemical properties and the highest sensory scores after 12 days of storage were obtained for the samples wrapped in the films incorporated with 1% AJEO and 4 wt% CHNF.

Shirazi balangu (Lallemantia royleana) seed mucilage: Chemical composition, molecular weight, biological activity and its evaluation as edible coating on beefs

In this study, Lallemantia royleana seed mucilage (LRSM) was extracted from whole seeds using hot-water extraction. The structural information (monosaccharide compositions and molecular weight analysis), chemical composition (moisture, protein, ash, fat and carbohydrate), biological activity (antimicrobial, total phenol content and antioxidant activity) and effect LRSM edible coating on population of microbial pathogens (total viable count (TVC), psychrotrophic bacteria, Escherichia coli, Staphylococcus aureus and fungi), chemical changes (thiobarbituric acid, peroxide value and pH) and sensory attributes (color, odor and total acceptability) of the beef slices at 4°C for 18days (0, 3, 6, 9, 12, 15 and 18) were determined. The LRSM had 76.74% carbohydrate, 3.86% protein, 9.92% ash and 9.48% moisture. LRSM is a high molecular weight (1.19×106Da) polysaccharide, composed of galactose (36.28%), arabinose (35.96%), rhamnose (15.18%), xylose (7.38%) and glucose (5.20%). The LRSM total phenolic content and antioxidant activity (IC50) were equal to 82.56±1.6μgGAE/mg and 528.54±0.35μg/ml, respectively. The results showed that, the beef shelf life based on TVC for samples control, LRSM, LRSM+1% AHEO, LRSM+1.5% AHEO, and LRSM+2% AHEO were 6, 9, 9, 12, and 15days, respectively. There was no significant difference between LRSM+1% AHEO and LRSM samples, but the TVC in first one had slight changes than LRSM. Compared to the control samples, LRSM extended the microbial shelf life, oxidative stability and sensorial acceptability of beef by 3, 6 and 6days, respectively.