Effects of Chitosan Coating with Green Tea Aqueous Extract on Lipid Oxidation and Microbial Growth in Pork Chops during Chilled Storage

Abstract

Lipid oxidation and microbial growth are the major causes of meat quality deterioration. Natural ingredients in meat products have been proposed as a strategy to prevent quality deterioration during cold storage. This study aimed to assess the effects of added chitosan coating, alone and in combination with green tea water extract (GTWE), on the quality of pork chops during prolonged cold storage. For evaluating oxidative and antimicrobial stabilities, 72 fresh pork samples were subjected to four treatments (n = 18 per treatment): T0 (non-coated chops without GTWE); T1 (chitosan-coated chops without GTWE); T2 (chitosan-coated chops plus 0.1% of GTWE); and T3 (chitosan-coated chops plus 0.5% of GTWE). Pork samples were stored at 0 °C and subjected to physicochemical evaluation (pH, colour, and lipid oxidation) and microbiological analyses (mesophilic and pyschrotrophic counts) at 0, 5, 10, 15, 20 and 25 days of storage. GTWE presented high total phenolic content (> 500 mg gallic acid equivalents/g); the incorporation of chitosan coatings increased (p < 0.05) free radical scavenging activity (FRSA, >90% of inhibition) and microbial growth inhibition (>50% for all tested pathogens), depending on the concentration. Further, GTWE inclusion in pork samples (T2 and T3) reduced (p < 0.05) pH, lipid oxidation and microbial counts, as well as colour loss in meat and bone throughout storage. Chitosan coating with GTWE could be used as an additive for the preservation of pork meat products.

Green Coating Polymers in Meat Preservation

“…Chitosan was dissolved in glacial acetic acid, and the green tea extract was further added by homogenization. Findings of this study showed that the coating served as an excellent antioxidant material against lipid peroxidation in pork chops [77]. Those findings were confirmed in another similar study that used bamboo vinegar blended with chitosan to develop an active edible coating of pork chops [78].…”

“…Chitosan-based edible coatings were already proven as an effective active packaging material for meat preservation during storage, especially as their preservative efficiency was further enhanced when fabricated with other natural antimicrobials and antioxidants, such as cinnamon oil, gallic acid, and polylysine [72][73][74][75][76]. Montaño-Sánchez et al [77] investigated the anti-lipid oxidation properties of green edible coating from chitosan in the presence of bioactive green tea leaf extract. The authors extracted bioactive compounds using maceration.…”

Chitosan coating incorporated with grape seed extract and Origanum vulgare essential oil: an active packaging for turkey meat preservation

“…Edible films and coating manufactured from natural components like proteins, polysaccharides and lipids, or their combination, are an excellent alternatives of non-biodegradable plastics used commonly in food packaging because they are biodegradable, edible, environmental friendly and have low prices [22,23]. Chitosan is a linear, non-toxic, biocompatible and biodegradable polysaccharide produced through deacetylation of the chitin existed in the crustacean shells [7,24].…”

“…It is well known as an antimicrobial and antioxidant compound that is identified as generally recognized as safe (GRAS) [25,26]. This biopolymer can successfully be used for production of edible films and coatings for food packaging [23].…”

Influence of antioxidative and antibacterial activity of sage aqueous extract and chitosan formulation on chicken burger quality

“…Chitosan formulation is directly added to meat and meat products (7,8), or alternatively, chitosan coatings are applied on the product surface (35). The antibacterial and antioxidative effects of chitosan coatings intended for meat products can be enhanced via the addition of plant formulations (18).…”