Fortification of puffed biscuits with chitin and crayfish shell: Effect on physicochemical property and starch digestion

Chitin is a polysaccharide and possesses numerous beneficial properties such as nontoxicity, biodegradability and biocompatibility, which draws much attention to its applications in food. Crayfish shell is a source of chitin alongside an antioxidants and a potential source of beneficial dietary fiber. In this study, chitin (CH) and crayfish shell (CS) with different concentrations were used to study their impact on pasting characteristics of flour mixture (wheat flour and glutinous rice flour) and influence on physicochemical and starch digestion property of puffed biscuit. The Rapid Visco-Analyzer results showed that the viscosity of powder mixture was decreased with the ratio of CH and CS increased. CH resulted in lowest peak viscosity and breakdown values of mixed powder. It was indicated that increasing amounts of CH and CS led to significantly reduced moisture content, expansion ratio but raised density of biscuits. CH and CS inhibited starch digestion and promoted a remarkable increase (P < 0.05) of resistant starch (RS) content. The hydrolysis kinetic analysis suggested a decelerating influence of CH on the hydrolysis content with lower values of equilibrium hydrolysis percentage (C∞) while CS on hydrolysis rate with lower kinetic constant (K). The estimated glycemic index (eGI) of the CH (15-20%) samples were below 55. These results are of great significance in delaying starch digestion and provided a better choice in design of fried puffed snacks for special crowd with chronic diseases such as diabetes, cardiovascular disease, and obesity.

Potato Industry By-Products as a Source of Protein with Beneficial Nutritional, Functional, Health-Promoting and Antimicrobial Properties

Most potato proteins are fractions of albumin and globulin, soluble in water and in water and salt solutions, respectively; these are patatin glycoproteins, with a pIs in the range of 4.8–5.2. This group of proteins is typical of potato and they are referred to as patatin or tuberin. Around 30–50% of soluble potato proteins comprise numerous fractions of protease inhibitors with a molecular weight in the range of 7–21 kDa; they are often heat-resistant, showing a wide spectrum of health-promoting effects. The nutritional value of proteins is related to the content of amino acids, their mutual proportions and digestibility. Natural proteins of the patatin fraction are characterized by favorable functional properties, including foam formation and stabilization, fat emulsification or gelling. Native potato proteins may also exhibit beneficial non-food properties, such as antimicrobial or antitumor, as well as antioxidant and antiradical. Depending on the method of isolation and the applied factors, such as pH, ionic strength and temperature, the directions of using potato protein preparations will be different.

Effect of wheat and corn germs addition on the physical properties and crackers sensory quality

Crackers are a potential material for the addition of cereal germs as a functional ingredient because they are a popular bakery item. The suitability of cereal germs for crackers production was investigated in this study. The effect of cereal germs incorporation to wheat dough (at level 5, 10 and 15%) on the physical properties (specific volume, volume index, width, thickness and spread ratio) and sensory parameters (appearance, firmness, taste, odor and overall acceptability) of cracker were evaluated. It was shown that wheat and corn germ addition to crackers resulted in decreased specific volume from 1.65 cm3.g-1 (control sample) to 1.52 cm3.g-1 (10% corn germs addition) and volume index 3.20 cm (control sample) to 2.57 cm (15% wheat germ), whereas spread ratio increased from 4.71 (fine wheat flour) to 5.06 (15% corn germ). No significant differences were found between the values obtained for width and thickness for crackers supplemented with 5% wheat germ to control sample. Addition of corn germ and wheat germ at level 15% caused decrease volume index of crackers about 13 and 20%. On the other hand enriched crackers of wheat germ and corn germ at level 15% was increment spread ratio by 5 and 7%. Regarding to sensory properties the overall appearance was affected significantly by addition of wheat and corn germ. Higher addition of wheat and corn germ in the crackers adversely affected firmness, taste and odor of final products. In generally, sensory properties of crackers were markedly affected with addition of cereal germs. The most significant differences were observed in appearance of crackers, when the 15% of wheat or corn germs were added (15 and 30% decreasing of this attribute in compare to control sample, respectively). The results of sensory analysis also showed that the crackers incorporated with wheat germs up to 10% level resulted in products with good acceptability. 

Anthocyanin and antioxidant activity of snacks with coloured potato

Coloured-fleshed potatoes of four varieties were used as raw material for coloured flour and fried snack production. The effects of thermal processes traditionally used in dried potato processing and in snack pellet manufacturing on anthocyanin profiles, total polyphenols and antioxidant properties of obtained half- and ready products were studied. There was a significant influence of potato variety on the experimental flour and snack properties. Flours with the highest antioxidant activities were obtained from Salad Blue and Herbie 26 potatoes; however, the flour prepared from the Blue Congo exhibited a much higher total polyphenol and anthocyanin content. Snacks produced with coloured flour had 2-3 times higher antioxidant activities, 40% higher contents of polyphenols, attractive colour and better expansion compared to control samples. The lowest losses of anthocyanins during snack processing were in snacks with flour from the purple-fleshed Blue Congo and red-fleshed Herbie 26.