The market of functional foods and beverages develops dynamically. Biological activities of many food components which occur naturally become an issue of many scientific and industrial interests. The structural and chemical changes occurring during the proteins processing lead to the release of bioactive peptides. Their multifunctional activity is based on their structure and other factors including e.g. hydrophobicity, charge, or microelements binding properties. This article focuses on peptides with other physiological and functional activities such as antithromobotic, antioxidative, antibacterial and antifungal, sensory, and improving those nutritional value of food.

Although there are numerous methods for quantitative determination of antioxidative vitamins: C, E, and A, there are no methods favourable for the broadly understood analytic practice – they have various faults and limitations or require expensive apparatus. Therefore, we have elaborated modifications of valuable spectrophotometric methods for determination each of those vitamins, which originally could not be applied for laboratory practice from various regards. They are based on: for vitamin C – colour reaction with periodically prepared phosphotungstate reagent; for vitamin E – colour reaction with batophenanthroline, FeCl₃ and H₃PO₄; for vitamin A – spectrophotometric measurement of extracts of tested samples. Control tests showed complete correctness of analytic parameters obtained with those modifications with preservation of advantages of the original methods. Therefore they can be successfully implemented to the routine clinical analyses’. The elaborated modifications can also be used for determination of the a/m vitamins in foodstuffs, for example: in juices, milk and homogenates or extracts of solid food.

The objective of the investigations performed was to assess the antioxidant properties of the seeds and peels of selected fruits. The antioxidant activity as well as total polyphenol and tannin content were determined. The results obtained revealed essential diversities of the analysed parameters among the material examined. The peels were characterized by higher ability to scavenge free radicals and higher polyphenols concentration than the seeds, particularly those of citrus fruits imported to Poland. The highest antioxidant activity was observed in the peels of the Šampion cultivar of apples and white grapes, and in the seeds of the Idared cultivar apples and oranges. Tannins play a meaningful role as antioxidants in grape, apple and goosberry fruits. The peels and seeds of various fruits, which are waste products in fruit and vegetable industry, may be a potential source of antioxidants.

In the study the effect was assessed of sample processing with solutions containing inhibitors of enzymatic browning and tissue softening and sucrose on the quality of minimally processed apples. Ascorbic acid, citric acid, 4-hexylresorcinol, sodium chloride, calcium chloride, sodium lactate, calcium lactate and sucrose were used as inhibitors. The application in apple slice processing of a solution containing 1% ascorbic acid, 0.005% 4-hexylresorcinol, 0.5% calcium chloride, 20% sucrose effectively inhibited the browning and softening of apple slices during storage. Moreover, it had an advantageous effect on the other sensory attributes, resulting in a product of very high quality. A good quality product is obtained using a solution of citric acid and sucrose.

Soybean daddawa is a popular condiment made by fermenting dehulled seeds of soybean (Glycine max); it is commonly used in soups in the soybean growing areas of Nigeria. Soybean daddawa prepared using three different processing methods (traditionally fermented seeds, seeds fermented with salt (NaCl) and seeds fermented with starter cultures) was evaluated for biochemical changes in ambient storage conditions. The fermented product was assessed for pH, titratable acid, peroxide, free fatty acids, antioxidant capacities as well as water and fat absorption capacities as indices of deterioration. pH of stored samples increased in the alkaline range, titratable acidity of samples also increased with storage. Peroxide values of samples increased significantly from 3.87 meq/kg on first day of storage to 30.73 meq/kg in two weeks on naturally fermented soy daddawa samples. Values obtained for FFA also increased with storage period, while, antioxidant capacity, water and fat absorption capacities decreased drastically with storage. Although, the values obtained for the parameters monitored differed with the methods of processing, the differences were not significant (p > 0.05) however; values obtained at the start of the experiment and after 14 days of storage differed significantly. Most of the biochemical changes in monitored functional properties of the samples became noticeable on the 4th and 6th day of storage. The results are discussed with reference to food safety and shelf- -life of the product.

Sensory parameters of gluten-free bread depend on the amount and type of hydrocolloids used as gluten replacers, as this determines interactions between them and starch, which is the main component of dough. The evaluation of gluten-free breads supplemented with various amounts of guar gum, pectin and xanthan, proved that bread with addition of xanthan has higher volume in comparison with pectin-guar standard. Higher amount of xanthan resulted in a decrease of bread hardness on the day of baking and after 72 hours of storage. Bread baked with equal amounts of all hydrocolloids (recipe IV) displayed best quality parameters. The amount of free amylose in crumb extract depended on the extent of starch gelatinisation, influenced by proportions of pectin, guar gum and xanthan in the mixture of hydrocolloids.

Reactive oxygen species are postulated to be involved in systemic inflammation and oxidative stress in patients with obesity. Activated polymorphonuclear neutrophils (PMNs) generate extremely high amounts of reactive oxygen species, but these are normally targeted at pathogens inside intracellular phagosomes. The same beneficial antimicrobial functions, if not controlled, contribute to the tissue damaging effects of inflammatory reactions. The evidence from conventional epidemiology strongly implies fruits and vegetables in protection against oxidative stress. In our study, the in vitro effects of Aronia melanocarpa juice on oxidative metabolism and apoptosis of neutrophils from obese and non-obese individuals has been investigated. We tested 15 obese patients (aged 45 ±9 years, women, BMI = 34 ±4.9 kg/m²). Nine healthy subjects (BMI = 22.2 ±1.6 kg/m²) were enrolled as controls. Neutrophils were isolated and oxidant production, in response to phorbol 12-myristate 13-acetate, was characterized by using luminol dependent chemiluminescence (CL) and flow cytometric dichlorofluorescin oxidation assay. Caspase-3 activity, a marker of apoptosis execution, in human neutrophils, measured by a cleavage of the fluorogenic substrate Ac-DEVD-AMC. Additional experiments to assess the direct toxic effect of the aronia polyphenols were also carried out. Neutrophils from obese individuals had a significantly higher H₂O₂ production and CL response compared to controls (p < 0.05). The oxidative metabolism of PMNs was decreased by aronia juice treatment in both of groups, obese and non-obese individuals. The caspase-3 activity depended on the time of aronia juice treatment and was markedly increased in phorbol-treated cells incubated with polyphenols for 24 hours. This natural product exert beneficial effects in cells and may, therefore, be useful in the treatment of obesity disorders.

Ultrasonic is a rapidly growing field of research, which is finding increasing use in the food industry for both the analysis and modification of food products. The sound ranges employed can be divided into high frequency, low energy diagnostic ultrasound and low frequency, high energy power ultrasound. The former is usually used as a non-destructive analytical technique for quality assurance and process control with particular reference to physicochemical properties such as composition, structure and physical state of foods. Nowadays, power ultrasound is considered to be an emerging and promising technology for industrial food processing. The use of ultrasound in processing creates novel and interesting methodologies which are often complementary to classical techniques. Various areas have been identified with great potential for future development: crystallisation, degassing, drying, extraction, filtration, freezing, homogenisation, meat tenderization, sterilization, etc. There is a wide scope for further research into the use of ultrasound in food processing both from an industrial and academic viewpoint.