Cold plasma is a new technology of promising potential to use as a part of technological extraction lines constructed to implement green chemistry solutions or simply to reduce resources in solvent-based extraction lines. The present study was undertaken to verify the effect of nitrogen cold plasma pre-treatment conducted for 8 min (20 kHz) on the content of antioxidants, antioxidant activity, the profile of volatile compounds, microbial count, pH and color measured in herb extracts (12 herbs: Echinacea purpurea; Salvia officinalis; Urtica dioica; Polygonum aviculare; Vaccinium myrtillus; Taraxacum officinale; Hypericum perforatum; Achillea millefolium; Sanguisorba officinalis; Leonurus cardiaca; Ballota nigra; Andrographis paniculata) obtained with its usage. The surface morphology of extracted herbs was examined as well. Herbs used for extraction were ground and suspended in water before cold plasma treatment, which is a novel approach not studied before. Most plasma-treated extracts were characterized by a higher content of polyphenols (11 out of 12). Content of flavonoids and anthocyanins increased in four extracts and in the case of anthocyanins was significantly higher in comparison to control (up to 77%). The antioxidant activity measured at least by one method (ABTS, DPPH, FRAP) was also higher in nine plasma-treated solutions. Moreover, plasma decreased total aerobic bacteria, affected the color and increased pH of the extracts. The surface structure of the plant material after the extraction process was significantly damaged, which probably led to a higher extraction yield of bioactive compounds and in consequence to the higher antioxidant activity of extracts obtained with the cold plasma treatment.

Electronic noses are devices able to characterize and differentiate the aroma profiles of various food, especially meat and meat products. During recent years e-noses have been widely used in food analysis and proved to provide a fast, simple, non-expensive and non-destructive method of food assessment and quality control. The aim of this study is to summarize the most important features of this analytic tool and to present basic fields and typical areas of e-nose use as well as most commonly used sensor types and patterns for e-nose design. Prospects for the future development of this technique are presented. Methods and research results presented in this manuscript may be a guideline for practical e-nose use.

The growing number of people at high risk of cardiovascular disease development contributed to both changes in diets by consumers and the reformulation of food products by food producers. Cardiovascular diseases are caused by the i.a. consumption of meat that contains animal fat rich in saturated fatty acids (SFA). The use of fat substitutes in meat seems to be a promising tool for the reduction of cardiovascular disease occurrence. In the presented study, beef fat was replaced at 0 (CO), 25 (S-25%), 50 (S-50%), 75 (S-75%), and 100% (S-100%) by a fat substitute in a form of a lyophilized hydrogel emulsion enriched with encapsulated açai oil. The chemical (TBARS, volatile compound profile, fatty acid profile, pH), and physical (TPA, consumer rating, L*a*b* color, cooking loss) analyses were performed on raw and grilled burgers subjected to storage at cold conditions (4 °C) in days 0 and 7. Burgers formulated with hydrogels had a higher content of polyunsaturated fatty acids (PUFAs) of about 32% (p < 0.05) and reduced SFAs by 22%. Reformulation of the burger resulted in lower nutritional indices of the atherogenicity index (AI) (0.8 for CO, 0.3 for S-100%, p < 0.05) and thrombogenicity index (TI) (1.8 for CO, 0.6 for S-100%, p < 0.05), as well as led to an increased h/H ratio (1.3 for CO, 3.9 for S-100%, p < 0.05). Furthermore the application of freeze-dried hydrogels reduced cooking loss. Moreover, consumers did not observe significant differences (p < 0.05) between the control and S-25% and S-50% burgers. Thus, the use of lyophilized hydrogels formulated with konjac flour and sodium alginate and enriched with encapsulated acai oil can be successfully applied as a fat substitute in beef burgers.