Antioxidative capacity of fresh kombucha cheese fortified with sage herbal dust and its preparations

Antimicrobial potential of kombucha fresh cheese with the addition of sage (Salvia officinalis L.) and its preparations

One of the main challenges in fresh cheese technology is its rather limited shelf life. Prolongation of the shelf life of fresh cheese has been the focus of numerous research studies and different strategies have been thus used. One of the strategies that could prolong the shelf life of fresh cheese, as well as increase its quality is the application of different starter cultures. As the antimicrobial capacity of sage (Salvia officinalis) has been proven, the possibility of reusing its by-product obtained from a tea factory could be a significant step towards the retention of environmental equilibrium and simultaneous production of food with additional functional value. Therefore, the aim of our research was to examine the antimicrobial potential of kombucha fresh cheese with the addition of ground herbal sage, sage essential oil and sage supercritical fluid extract, and compare it with fresh cheese obtained from a commercial starter culture. In order to examine the antimicrobial activity of kombucha fresh cheese produced with the addition of sage preparations, the produced samples were artificially contaminated with common foodborne contaminants: Listeria monocytogenes, Escherichia coli and Staphylococcus aureus. The obtained results revealed that the addition of sage essential oil and herbal ground sage increased the antimicrobial activity during the 30 days of storage against E. coli in kombucha fresh cheese (decrease of 2.9 and 2.5 log CFU g^-1, respectively). Implementation of sage significantly increased the antimicrobial activity of the fresh cheese produced with a commercial XPL-1 starter culture against L. monocytogenes (essential oil - 0.9 log CFU g^-1 and ground sage - 1.2 log CFU g^-1). In the XPL-1 sample, the growth of S. aureus was inhibited by the addition of ground sage - a decrease of 1.4 log CFU g^-1. Analysis of the total phenols revealed their 5-fold higher content in the kombucha fresh cheeses compared to the samples obtained by the XPL-1 starter culture. These results correlate with the higher antimicrobial activity of the kombucha fresh cheese samples compared to the XPL-1 samples. According to our results, industrial waste, obtained as a by-product in sage (Salvia officinalis) filter tea production, can be efficiently used in fresh cheese technology in order to increase the antimicrobial activity against L. monocytogenes, E. coli and S. aureus.

Lipid Extracts Obtained by Supercritical Fluid Extraction and Their Application in Meat Products

Supercritical fluid extraction (SFE) has been recognized as the green and clean technique without any negative impact on the environment. Although this technique has shown high selectivity towards lipophilic bioactive compounds, very few case studies on the application of these extracts in final products and different food matrices were observed. Considering the recent developments in food science and the increasing application of supercritical extracts in meat products in the last decade (2012–2022), the aim of this manuscript was to provide a systematic review of the lipid extracts and bioactives successfully obtained by supercritical fluid extraction and their application in meat products as antioxidant and/or antimicrobial agents. Lipophilic bioactives from natural resources were explained in the first step, which was followed by the fundamentals of supercritical fluid extraction and application on recovery of these bioactives. Finally, the application of natural extracts and bioactives obtained by this technique as functional additives in meat and meat products were thoroughly discussed in order to review the state-of-the-art techniques and set the challenges for further studies.