Tubular Cellulose from Orange Juice By-Products as Carrier of Chemical Preservatives; Delivery Kinetics and Microbial Stability of Orange Juice

Tubular Cellulose Composite as a Vehicle for the Development of Meat Products with Low Nitrite Content

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.

New Perspectives to Enhance Wastes and By-Products from Agro-Food Processing

The exploitation of by-products and waste from the agri-food industry represents a sustainable approach within the frame of the circular economy, the basis of the European Green Deal and ecological transition [...].

Water usability as a descriptive parameter of thermodynamic properties and water mobility in food solids

A classic problem in preservation is the microbes can grow in low-moisture foods. In this paper, the water sorption, and thermodynamic properties of glucose/WPI solid matrices were measured, while their molecular mobility was analyzed and associated with the microbial growth of D. Hansenii at various a_w and 30 °C. Although the sorption isotherms, T_g, and relaxation processes of studied matrices were affected by a_w and WPI, the microbial growth showed highly dependent on water mobility rather than a_w. Hence, we introduced water usability (U_w), derived from the mobility difference between system-involved water and liquid pure water explicating from the classical thermodynamic viewpoint, to describe the dynamic changes of water mobility in glucose/WPI matrices. Despite to a_w, the yeast growth rate was enhanced at high U_w matrices concomitantly with a rapid cell doubling time. Therefore, the proposed U_w provides a better understanding of the water relationships of microorganisms in food preservation.

Advancements in the Use of Fermented Fruit Juices by Lactic Acid Bacteria as Functional Foods: Prospects and Challenges of Lactiplantibacillus (Lpb.) plantarum subsp. plantarum Application

Lactic acid fermentation of fresh fruit juices is a low-cost and sustainable process, that aims to preserve and even enhance the organoleptic and nutritional features of the raw matrices and extend their shelf life. Selected Lactic Acid Bacteria (LAB) were evaluated in the fermentation of various fruit juices, leading in some cases to fruit beverages, with enhanced nutritional and sensorial characteristics. Among LAB, Lactiplantibacillus (Lpb.) plantarum subsp. plantarum strains are quite interesting, regarding their application in the fermentation of a broad range of plant-derived substrates, such as vegetables and fruit juices, since they have genome plasticity and high versatility and flexibility. L. plantarum exhibits a remarkable portfolio of enzymes that make it very important and multi-functional in fruit juice fermentations. Therefore, L. plantarum has the potential for the production of various bioactive compounds, which enhance the nutritional value and the shelf life of the final product. In addition, L. plantarum can positively modify the flavor of fruit juices, leading to higher content of desirable volatile compounds. All these features are sought in the frame of this review, aiming at the potential and challenges of L. plantarum applications in the fermentation of fruit juices.