Salmonella survival during soft-cooked eggs processing by temperature-controlled water circulator

Valorization of bio-waste eggshell as a viable source of dietary calcium for confectionery products

BACKGROUND

The market of innovative foods is developing very dynamically and consumers are paying increasingly more attention to the health properties of the food offered. In addition, many studies on food consumption indicate a deficiency of minerals in the diet and experts suggest that the consumption of fortified functional foods in a selected group of consumers may contribute to the improvement of their health and quality of life.

RESULTS

The aim of the work was to present the possibility of using bio-waste eggshell as a source of calcium in designing confectionery products. A snack with high calcium (0.567 g Ca kg^-1 of product) and fiber (11.44 g kg^-1 of product) content and potentially high calcium bioavailability was prepared. The results of the sensory expert-based assessment indicate a high (6-7 conventional units) overall sensory quality (OSQ) of the four flavor versions of the product during up to 3 months storage. In order to accurately illustrate the effect of storage time on the quality of the samples, texture analysis was carried out and the presented results indicate low correlations (r = -0.5554; r = -0.1494) between instrumentally measured hardness and sensory attribute of crispness, as well as hardness and OSQ, respectively.

CONCLUSION

It is possible to reuse bio-waste eggshells as a calcium-fortifying substance for food design. The addition of powdered eggshells to food is an interesting direction, both for nutritional reasons (high concentration of calcium and optimal bioavailability) and also for environmental protection (reduction of post-production waste). © 2021 Society of Chemical Industry.

Effect of curing and heat treatments on the Salmonella survival and physicochemical properties of chicken egg yolk

Cured egg yolk is a novel gastronomic preparation, which a salt and sugar mixture gradually diffuses into the egg yolk, promoting its solidification from the exterior to the inner parts and greatly concentrates fat and flavor. This study was undertaken to analyze the effect of curing and its association with heat treatments on the Salmonella survival and physicochemical properties of chicken egg yolks. Contaminated egg yolks (8.4 log₁₀ CFU/g) were covered by a mixture of sugar and salt and stored at 4.5 °C for curing, for 2, 24, 72 and 144 h. The cured yolks were subjected to the heat treatments: 62 °C for 30 min in temperature-controlled water circulator or at 80 °C for 3 h in oven. None of the treatments promoted the complete inactivation of Salmonella (detection limit of 100 CFU/g). However, Salmonella populations were significantly reduced (p ≤ 0.05) when heat processes were applied, reaching a maximum reduction of 5.6 log₁₀ CFU/g when the yolks were cured for 2 h and subsequently treated in temperature-controlled water circulator (62 °C for 30 min). This treatment kept the physicochemical properties similar to the ones without heat treatment, while the oven treatment showed considerable changes on texture, water activity and visual color. In conclusion, the use of curing time of 2 h followed by temperature-controlled water circulator process can improve the safety of cured egg yolks made from high quality eggs. However, other methods should be considered and analyzed to promote a complete inactivation of Salmonella.