The Effect of a natural ingredient from plum by-products for the preservation of pork burgers

Introduction

Plum by-products (var. Cimson Glo) contain healthy bioactive compounds, such as fibre and phenolic compounds with antioxidant and antimicrobial activity. Consumer concern about chemical additives in meat foods has been increasing. Natural ingredients are a good alternative to replace chemical additives and to preserve meat products. The valorisation process using high hydrostatic pressure (HHP) preserves food products by reducing microbiological counts while maintaining levels of bioactive compounds. The main objective of this study was to evaluate the effect of an ingredient from plum by-products for the preservation of pork burgers.

Methods

In order to obtain a bioactive ingredient from plum by-products (var. Crimson Globe), fruits were ground to a fine puree. It was blanched at 80°C for 1 min and treated with HHP (600 MPa 5 min at 10°C). HHP technology does not inactivate the polyphenol oxidase enzyme (PPO), so a previous heat treatment (blanching) was necessary to inactivate the PPO.

Three lots of pork burgers were elaborated: control (traditional recipe without additives or ingredients), sulphite (with methabisulfie), plum 1% (with the ingredient). Instrumental colour, lipid oxidation (TBA-RS), and protein oxidation (carbonyls) were measured in the burgers. In addition, sensory analysis was performed by a panel of 8 expert tasters. The burgers were stored in refrigeration for 8 days.

Results

After 8 days of refrigerated storage, the burgers with the natural plum ingredient presented a higher red colour (CIE a*) and reduced protein oxidation compared to the control burgers. Lipid oxidation development was also lower in burgers with plum than the burgers with sulphites. In the sensory evaluation, the tasters evaluated the burgers with natural ingredients, and no differences were noticed with respect to other formulations.

Conclusion

The natural ingredient from plum by-product is a good alternative for preserving pork burgers. Healthier burgers could be obtained by replacing sulphites with the developed ingredient.