Search

The purpose of our study was to evaluate the effect of the addition of Lactobacillus casei and Lactobacillus plantarum to Cheddar cheese on the antioxidant properties during its ripening time and after simulated gastrointestinal conditions. During the whole ripening time, the scavenging of DPPH and hydroxyl radicals both reached their maximum activity at the 16th week, while reducing power activity was reached at the 20th week. The antioxidant values of probiotics cheese were significantly higher than that of control (p< 0.05). Similar results were found after simulated gastrointestinal conditions. The simulated gastric digestion can significantly reduce the activity of DPPH radicals-scavenging (p< 0.05), but after intestinal condition, the values came back to the same level compared with that before digestion. The electrophoretic patterns indicated that adding probiotic to cheese could promote the hydrolysis of protein to enhance the antioxidant activity, especially with mixed probiotics. The addition of probiotic bacteria to Cheddar cheese had nearly no effect on its composition, texture profile analysis, and sensory analysis. [ABSTRACT FROM AUTHOR]

Proteolysis degree, ACE-inhibitory (ACE-I) activity, water-soluble peptide profiles of Cheddar cheese with different probiotics were determined during digestion period and were comprehensively compared to evaluate the influence of digestion and the addition of different probiotics. After digestion, further hydrolysis of protein led to the production of more low molecular weight peptides, and ACE-I peptides with higher activity were released. ACE-I activity of Cheddar cheese with Lactobacillus helveticus (B4, 86.06%) was significantly (P < 0.05) higher than other cheese groups. Three ACE-I peptides were uniquely presented in B4 before digestion and more new ACE-I peptides were released after digestion. Meanwhile, cheese with Lactobacillus rhamnosus was more likely to produce anti-digestion ACE-I peptides. Most of ACE-I peptides come from β-casein. Hydrophobic amino acids Val, Phe, Pro, Tyr, Leu, and basic amino acids Arg, Lys at the C-terminal were more responsible for the formation of ACE inhibitory peptides that resist digestion. This research provides the basis to increase the exploitation of the health benefits of Cheddar cheese with probiotic. • After digestion, the ACE-I activity of cheeses increased, and the amount of peptides decreased. • Anti-digestion ACE-I peptides were more likely to release from cheese with L.rhamnosus. • Cheese with L. helveticus had the highest ACE-I activity before and after digestion. • Six ACE-I peptides belonging to β-casein existed in all cheese and can be resist to digestion. • The C-terminal of anti-digestion ACE-I peptides mainly contained hydrophobic amino acids. [ABSTRACT FROM AUTHOR]

In our current study, high-intensity ultrasound was employed to enhance the bioactive, functional, structural, and digestibility properties of potato protein. Potato proteins were extracted from potato fruit juice (PFJ), both potato protein powder and patatin were exposed to ultrasound at 600 W for 10, 15, and 20 min. We observed noticeable alterations in the functional and bioactive properties of both potato powder and patatin. Ultrasound treatment for 20 min was the optimal for the enhancement of both functional and bioactive properties. There was a significant increase of 30%, 33% for DPPH, and 16%, 23% OH radical scavenging activity for potato protein powder and patatin. Also, an increase of 12% in the digestibility of high intensity ultrasound (HIU) treated potato protein was observed. Furthermore, fourier-transform infrared spectroscopy FTIR showed a substantial decrease in the amide I and amide II band for treated samples. Scanning electron microscope (SEM) showed the smallest fragments for both potato protein (PP) and patatin in HIU treatment for 20 min. The tested functional properties, including emulsifying ability index (EAI), emulsifying stability (ESI), foaming ability, solubility, and zeta potential, were significantly enhanced. There was a significant decrease in particle size, foaming stability in both potato protein powder and patatin. [Display omitted] • Potato protein and patatin "fractions were" treated with high intensity ultrasound. • The protein functional properties were increased by using ultrasound for 20 min. • Ultrasound treatment increased "proteins" bioactivity upto 35%. • Digestibility of potato proteins was improved about 15%. [ABSTRACT FROM AUTHOR]