Comparison of quality and microstructure of chokeberry powders prepared by different drying methods, including innovative fluidised bed jet milling and drying.

The study assessed the functional properties, microstructural features and sensory characteristics of chokeberry powders obtained by the new fluidised bed jet milling and drying method as compared to other drying methods such as freeze-drying, vacuum drying and convection drying. The new method was based on simultaneously drying and milling plant material which had been subjected to partial air drying at 70 °C prior to this treatment. The technique resulted in the production of good quality fruit powders with high vitamin C and polyphenolic content, as well as high antioxidant activity. Favourable physiochemical characteristics and sensory qualities were also observed together with low water activity. The new fluidized bed jet milling and drying therefore compared very favourably with freeze-drying, vacuum drying and convection drying when considering the content of bioactive substances, physiochemical features and the sensory quality of the prepared powders.

The occurrence of resveratrol in foodstuffs and its potential for supporting cancer prevention and treatment. A review

Over recent years, there has been increasing interest noted in those active substances derived from plants that show potential for preventing cancer development. The most promising candidate is resveratrol which can be found in large amounts in the skin of grapes, tomatoes and in red wine. Its beneficial effects on the human body are seen both in prevention and therapy. The anti-carcinogenic action of resveratrol is linked with its ability to neutralise reactive oxygen species and to modulate cellular processes such as apoptosis, and both cancerous cell proliferation and differentiation. This article presents the characteristics of resveratrol as a bioactive compound derived from natural sources exhibiting anti-cancer properties, which, because of a wide spectrum of biological activities may be used in the prevention of cancer. Many in vitro and animal-based studies have demonstrated such preventative anti-cancer action in the colon, prostate, breast and lungs. The beneficial effects of resveratrol are also presented when adopted as a support to conventional treatments of cancer using chemo- and radio-therapy.

Assessing polyphenols content and antioxidant activity in coffee beans according to origin and the degree of roasting

Background: The roasting stage constitutes a key component in the manufacturing process of natural coffee because temperature elicits changes in bioactive compounds such as polyphenols and that Maillard-reaction compounds appear, thus affecting the product's sensory and antioxidant properties. Actual contents of these compounds may depend on which region the coffee is cultivated as well as the extent to which the beans are roasted Objectives: To determine polyphenols content and antioxidant activity in the 'Arabica' coffee type coming from various world regions of its cultivation and which have undergone industrial roasting. Also to establish which coffee, taking into account the degree of roasting (ie. light, medium and strong), is nutritionally the most beneficial Materials and Methods: The study material was natural coffee beans (100% Arabica) roasted to various degrees, as aforementioned, that had been cultivated in Brazil, Ethiopia, Columbia and India. Polyphenols were measured in the coffee beans by spectrophotometric means based on the Folin-Ciocalteu reaction, whereas antioxidant activity was measured colourimetrically using ABTS+ cat-ionic radicals Results: Polyphenol content and antioxidant activity were found to depend both on the coffee's origin and degree of roasting. Longer roasting times resulted in greater polyphenol degradation. The highest polyphenol concentrations were found in lightly roasted coffee, ranging 39.27 to 43.0 mg/g, whereas levels in medium and strongly roasted coffee respectively ranged 34.06 to 38.43 mg/g and 29.21 to 36.89 mg/g. Antioxidant activity however significantly rose with the degree of roasting, where strongly roasted coffee had higher such activity than lightly roasted coffee. This can be explained by the formation of Maillard-reaction compounds during roasting, leading then to the formation of antioxidant melanoidin compounds which, to a large extent, compensate for the decrease in polyphenols during roasting Conclusions: Polyphenols levels and antioxidant activities in the studied Arabica coffee beans that had undergone roasting depended on the cultivation region of the world. Longer roasting caused a significant decline in polyphenols compound levels (from 7.3% to 32.1%) in the coffee beans. Antioxidant activities of coffee increased with roasting, despite reduced levels of natural antioxidants. From a nutritional standpoint, the most favoured coffees are those lightly or medium roasted

Spent yeast as natural source of functional food additives

Spent yeasts are by-products arising from beer and wine production which over many years have been chiefly used as feed additives for livestock. They contain many valuable and bioactive substances which has thereby generated much interest in their exploitation. Up till now, the main products obtained from beer-brewing yeasts are ß-glucans and yeast extracts. Other like foodstuffs include dried brewer's yeast, where this is dried and the bitterness removed to be fit for human consumption as well as mannan-oligosaccharides hitherto used in the feed industry. ß-glucans constitute the building blocks of yeast cell walls and can thus be used in human nutrition as dietary supplements or serving as food additives in functional foods. ß-glucans products obtained via post-fermentation of beer also exhibit a high and multi-faceted biological activity where they improve the blood's lipid profile, enhance immunological status and have both prebiotic and anti-oxidant properties. Yeast extracts are currently being used more and more to enhance flavour in foodstuffs, particularly for meat and its products. Depending on how autolysis is carried out, it is possible to design extracts of various meat flavours characteristic of specific meats. Many different flavour profiles can be created which may be additionally increased in combination with vegetable extracts. Within the food market, yeast extracts can appear in various guises such as liquids, pastes or powders. They all contain significant amounts of glutamic acid, 5'-GMP and 5'-IMP nucleotides together with various amino acids and peptides that act synergistically for enhancing the flavour of foodstuff products. Recent studies have demonstrated additional benefits of yeast extracts as valuable sources of amino acids and peptides which can be used in functional foods and dietary supplements. These products possess GRAS status (Generally Recognised As Safe) which thereby also adds further as to why they should be used as natural food additives that are functional.

Beverage osmolality as a marker for maintaining appropriate body hydration.

Background: Osmolalities can be useful markers for determining whether given beverages are suited for maintaining an adequate hydration of the body. Losing 2% of body water relative to body mass reduces the efficiency of body function when undertaking physical effort by around 20%. Deficiencies in water intakes approaching 5-8% of body mass, double the impairment to the body's physical and mental functioning, whereas at a level of 10% the body becomes incapable of performing any sort of physical effort. For such reasons the body's hydration status is vital to its functioning. Objectives: To asses osmolalities as measured in various types of commercially available mineral waters and non-alcoholic beverages containing different amounts of extracts. Materials and Methods: Test materials were commercially available mineral waters (of low, medium and high mineral content) along with juices, nectars and drinks that are isotonic, energising and those described as being 'light' and sparkling. Osmolality was measured by the 800CL Osmometer instrument from TridentMed whilst the RL-type refractometer was used for determining extract values. Results: Isotonic drinks were found to have the same osmotic pressures as bodily fluids at 275 ­ 295 mOsm/kg water. The osmotic pressure in mineral waters depended on the extent of mineralisation and ranged from 13 mOsm / kg water (low mineral content) to 119 mOsm/kg water (high mineral content). Low osmolalities were also found in 'light' drinks (from 29.3 to 34 mOsm/kg water). Juices, nectars, energising drinks and colas typically have high sugar contents and have high osmolalities ranging 492 ­ 784 mOsm / kg water. Statistical analysis demonstrated significant associations (p < 0.05) between osmolalities and extract content in beverages as well as between osmolalities and mineral content in mineral waters. Upon factor analysis, it was possible to group the tested drinks according to similar osmolalities and extract content. Conclusions: Osmolalities measured in beverages are a marker that permits drinks to be classified into groups according to their tonicity and their ability to ensure that the body is properly hydrated; this becoming vital in cases when the body requires rapid body fluid replenishment.