ABSTRACT
Research background: Nitrite salts are among the most used preservatives in meat products as they ensure their safe consumption. Despite their positive effects on food safety and stability, many side effects on human health have been reported, leading to the need to reduce their use. Therefore, the aim of this study is to produce veal products with low nitrite content through low diffusion of potassium nitrite and to study their microbiological characteristics. Experimental approach: Edible tubular cellulose from leaf celery was produced and KNO2 was encapsulated in this material. This was achieved in two ways: by impregnation of tubular cellulose in a KNO2 solution under stirring and using starch gel as a stabilizer. Two samples of impregnated cellulose were applied on the surface of two veal samples of which one was stored at room temperature and the other at 3 °C. Similarly, two samples of cellulose with starch gel were applied on the surface of two veal samples of which one was stored at room temperature and the other at 3 °C. The KNO2 diffusion in different depths of the meat was measured and its effect on the microbiological characteristics of the meat was evaluated. Τhe experiment was carried out in duplicate. Results and conclusions: A satisfactory percentage of about 70 % of the initially encapsulated amount of KNO2 was diffused in the meat, while the rest remained in the pores of the delignified leaf celery. The migrating amount of KNO2 proved to be effective in preserving meat, as the microbiological load decreased significantly (especially within the first 12 h, from a decrease of 0.6 log CFU/g up to 2.4 log CFU/g). Novelty and scientific contribution: The demand for meat products with low nitrite content is constantly increasing and the results of the present study are promising for the development of this technology in scale-up systems and on an industrial scale. This innovative approach could lead to products with controlled diffusion of the preservatives.
ABSTRACT
The quality and safety of juices are assured mainly through heat treatments and chemical preservatives. However, there is a growing trend in the food industry for lowering energy and water demands, and the chemicals and additives that may have negative effects οn human health. Following that trend, in the present study, the reduced use of chemical preservatives in orange juice is proposed by using encapsulated sodium benzoate (SB) in tubular cellulose (TC), derived from orange pulp. The effects of SB concentration and contact time on SB encapsulation were evaluated. The use of the wet impregnation method, 12% w/v SB solution and 2 h of contact proved to be ideal for application in the juice industry. The use of starch gel resulted in a more stable composite (TC/SB-SG) with a slower SB delivery, showing its potential for future controlled delivery applications. Furthermore, similar delivery rates of SB in juice were noted at 25 and 2 °C. The TC/SB-SG proved capable of inhibiting the growth and reducing the numbers of spoilage microorganisms (yeasts and lactic acid bacteria). The results of the present study are promising for potential applications; however, more research is needed in order to evaluate the controlled delivery of SB in juice.
