Antibrowning effect of commercial and acid‐heat coagulated whey on potatoes during refrigerated storage

Abstract

Potato color turns to brown after some process such as peeling, cutting, and slicing. In this research, the effect of acid‐heat coagulated whey and commercial whey solutions on the color, polyphenol oxidase, phenylalanine ammonia‐lyase activity, malondialdehyde, hydrogen peroxide content of potatoes were compared with pure water (control) immersion and sodium hydrogen sulfide solution. According to color results, there was no significant (P > 0.05) difference was found in the L* and b* values, browning index, and whitening index of the treatment groups. The polyphenol oxidase activity of the sulfide and commercial whey solution groups decreased from the initial values on day 3 then increased over that value. The use of the whey solution in preventing polyphenol oxidase activity showed a similar curve with the use of the sulfide solution. A rapid increase was observed in the malondialdehyde and hydrogen peroxide values of all treatment groups during the first 3‐day storage. Practical Application Immersion of potato cubes to whey protein solution prevents the browning and inhibits polyphenol oxidase activity. The browning index of the samples was not affected by the immersing water or whey solutions

Effect of Heat Treatment on Nutritional and Chromatic Properties of Mung Bean (Vigna radiata L.)

“…The total flavonoid content (quercetin) of mung bean seed coat heated at 120 • C for 20-50 min increased from 2.93 ± 0.51 to 18.74 ± 0.41 (µg/mg); thus, the content was statistically significantly different from the heat processing time (Figure 3a) (p < 0.05). However, flavonoids are chemically reactive and easily oxidized to quinones; quinones can be condensed with other polyphenolic compounds to form dark-brown polymers [50]. The condensation of flavonoids to form a dark-brown mass may be closely related to the reduced L-value obtained in this study by thermal treatment of seed coats.…”

Effect of Yogurt Serum on Enzymatic and Oxidative Activity in Fresh-Cut Potatoes

“…The amount of water-soluble protein in YS was found to be 0.96 g/L. Proteins have antioxidant properties because they can eradicate free radicals and neutralize reactive oxygen species, and their thiol group content delays enzymatic browning. , It has been reported that immersion of cut potatoes in whey protein solution inhibits PPO activity up to the third day of storage . Titration acidity of YS was found to have 1.25% lactic acid equivalent.…”

“…20,25 It has been reported that immersion of cut potatoes in whey protein solution inhibits PPO activity up to the third day of storage. 19 Titration acidity of YS was found to have 1.25% lactic acid equivalent. In a study, it was reported that 1% lactic acid moderately prevented the browning of apple slices.…”

“…Many treatments have been used to inhibit enzymatic browning caused by PPO, such ascorbic acid, n -propyl gallate, glutathione, l -cysteine, citric acid, GABA, n -acetylcysteine, isoascorbic acid, cod peptide, melatonin, whey, and allicin. ,− Yogurt serum (YS), on the other hand, has never been used to prevent enzymatic browning and extend shelf life. Consumers prefer YS because it is both cheap and natural.…”

“…YS may be one of the natural substances that can slow down enzymatic browning due to its antioxidant peptides and thiol content. In fruits and vegetables, thiol-containing compounds such as cysteine, N -acetyl- l -cysteine, glutathione, and whey have been shown to be promising inhibitors of PPO. ,, As a consequence, our study focused on YS for delaying enzyme activity. A study of the enzymatic and nutritional quality of fresh-cut potatoes dipped in YS is given in this paper.…”