The addition of walnut leaf powder (WLP) at 0.2% and 0.5% as a natural antioxidant in salted pork meat patties during refrigerated storage for 15 days was investigated, and its efficiency was evaluated against butylated hydroxytoluene (BHT). Proximate composition, cooking yield, pH, total phenolic content, free radical scavenging activity, lipid peroxidation expressed as thiobarbituric acid reactive substances (TBARS) and sensory analyses were conducted on manufactured patties. The pork patties containing 0.5% WLP had lower TBARS values and higher antioxidant activity compared to the BHT added and control samples during the 15 days of refrigerated storage. Addition of WLP significantly (P < .05) reduced lightness and redness but increased the hue angle of pork patties. In the sensory evaluation, WLP produced satisfactory results concerning the appearance, flavor and overall acceptability. The results indicated the potential of walnut leaf powder to retard lipid oxidation and to enhance the quality of cooked ground pork meat.

This paper reports on the development of new emulsion gels containing a mixture of olive, chia and algae oil emulsified with soy protein isolate and stabilized by two different cold gelling agents, gelatin (EGEL) and chitosan (ECHIT), and to evaluate their potential use as pork backfat replacers in cooked pork patties. Reformulated patties were produced by half and full pork backfat replacement and compared to normal fat patties and reduced fat content patties made by replacing half of the added fat with water. Color parameters, pH and thermal stability of the emulsion gels were determined at processing and after 10 days of refrigerated storage. Proximate composition, fatty acid profile, technological properties and sensory attributes were evaluated after patty processing, while color parameters, pH and lipid oxidation were monitored in patties during 15 days of refrigerated storage (4 °C). Reformulated patties showed significant improvements of the lipid profile (lower saturated fatty acid content and n-6/n-3 ratio and higher long-chain polyunsaturated fatty acid content) as compared to the controls. In terms of technological properties, chitosan was more effective than gelatin as a stabilizer of the emulsion gel. All reformulated patties showed a good evolution of lipid oxidation during storage and acceptable sensory attributes.

The effects of walnut leaf powder (WLP), walnut leaf extract (WLE) and cherry stem extract (CSE) on the oxidative and color stability of cooked pork patties were determined and compared with 0.01% butylated hydroxytoluene (BHT) and control (without antioxidant). Instrumental color, pH, total phenolic content, antioxidant activity, thiobarbituric acid reactive substances (TBARS) and sensory attributes were determined on manufactured patties initially (time 0) and after 5, 10 and 15 days of refrigerated storage. Addition of walnut leaf extract to pork patties was more effective than cherry stem extract in controlling lipid oxidation and color changes during cold storage, in agreement with results from the in vitro antioxidant activity. The natural additives significantly (p<0.05) increased phenolic content and antioxidant activity in cooked pork patties as compared to control and BHT treated samples, throughout the storage period. After 15 days, the TBARS values were significantly (p<0.05) reduced from 3.01 in control patties to 2.43, 1.58, 1.83 and 1.19 mg malondialdehyde per kg samples in patties with BHT, WLE, CSE and WLP, respectively. Addition of extracts showed positive effects on sensory attributes, the highest scores being achieved by WLP treated samples.    ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********