Effect of Different Methods of Thermal Treatment on Starch and Bioactive Compounds of Potato.

The study examined the effects of various methods of thermal treatment of Lord cultivar potato tubers on changes in starch, polyphenols, vitamin C, antioxidant activity, and mineral compounds. Following heat treatment in order to determine further transformations of starch, the potatoes were stored at 2 °C/24 h. Changes in starch, bioactive compounds and antioxidant properties varied depending on the treatment method. In general, higher retention of bioactive compounds was noted for tubers treated with "dry" methods, such as microwaving or grilling than for tubers treated with "wet" methods, e.g., boiling in water, steam cooking or cooking in a combi oven. These samples were also characterised by a higher resistant starch content. Cold storage resulted in an increase in the proportion of resistant starch. Total phenols content ranged from 210.96 (boiling) to 348.46 mg/100 g DW (grilling) and vitamin C content ranged from 43.79 (boiling) to 68.83 mg/100 g DW (microwaving). DPPH radical scavenging activity was the highest for the grilled tubers. The results indicate microwaving and grilling as the most favourable thermal treatments of potato.

Fruit Physical Features, Phenolic Compounds Profile and Inhibition Activities of Cranberry Cultivars (Vaccinium macrocarpon) Compared to Wild-Grown Cranberry (Vaccinium oxycoccus).

This study analysed fruits of cranberry cultivars: Ben Lear, Bergman, Early Richard, Pilgrim and Stevens and compared them with wild-grown cranberry fruits. The fruits were characterised in terms of dimensions, colour, content of total phenolic compounds, flavonoids, proanthocyanidins and anthocyanins, and hydroxyl radical and trypsin inhibition activities. It was shown that the wild-grown cranberry fruits were characterised by much smaller dimensions and redder colour than fruits of the cranberry cultivars. The most phenolic compounds were found in the Early Richard fruits (357.6 mg/100 g fw), and they showed the highest antitrypsin activity. The highest anthocyanin content (60.6 mg/100 g fw) was determined in the Pilgrim fruits, while the Ben Lear fruits were the richest source of proanthocyanidins (27.9 mg/100 g fw). The antioxidant activity was correlated with the content of phenolic compounds, flavonoids and proanthocyanidins, while the antitrypsin activity was correlated with phenolic compounds and anthocyanin contents.

Effect of Fruit Pomace Addition on Shortbread Cookies to Improve Their Physical and Nutritional Values.

Fruit pomace remaining after juice extraction is still a source of bioactive compounds. Especially rich in these compounds is the pomace from blackcurrant fruit and from fruits of little-known horticultural plants, like: rowan, rosehip and elderberry. The addition of fruit pomace to bakery and confectionery products, especially to those made of white flour, may significantly enrich their composition with dietary fiber, vitamins and phenolic compounds. This study was aimed at determining the effect of 20 % addition of fruit pomace from rosehip, rowan, blackcurrant and elderberry on the properties of shortbread cookies. The pomace-containing cookies, compared to those without additives, were characterized by a darker color with a higher contribution of yellowness, and by higher hardness. The overall organoleptic assessment was comparable for all types of cookies, however the cookies with pomace were characterized by more perceptible taste and aroma, and were sourer. The extracts from pomace-supplemented cookies had a significantly stronger antioxidant capacity than that from the cookies without pomace, but they were ineffective in inhibiting lipid oxidation. The study showed that fruit pomace could improve the nutritional value of shortbread cookies. Furthermore, non-typical color of such a new product may be attractive to consumers.