Add time:08/27/2019         Source:sciencedirect.com

Onion bulbs (Allium cepa L. cv. Hysam) were stored under regular atmosphere (RA: 21% O2/0.1% CO2) and controlled atmospheres (CA2/2: 2% O2/2% CO2; and CA2/8: 2% O2/8% CO2) with 80±3% relative humidity (RH) at 0.5±0.5 °C for 9 weeks. Total pyruvic acid content (PY), changes in S-alk(en)yl-l-cysteine sulfoxide (ACSO) flavour precursors and alliinase activity were quantified before and after storage. Both PY and total ACSO contents were significantly increased by RA storage (9–11%) and significantly depleted by CA storage. PY and total ACSO contents were depleted by 4.8 and 19%, respectively under CA2/2, and by 13.5 and 22%, respectively under CA2/8. The proportion of individual ACSOs also changed during storage. Before storage, trans-(+)-S-(1-propenyl)-l-cysteine sulfoxide (PRENCSO) was the major ACSO (49.2%), followed by (+)-S-methyl-l-cysteine sulfoxide (MCSO) (31.5%) and (+)-propyl-l-cysteine sulfoxide (PSCO) (19.3%). The proportion of PCSO was reduced under RA and CA2/2, with a concomitant increase in the proportion of MCSO. The reverse occurred under CA2/8. The protein content declined under all treatments, although alliinase specific activity increased under RA and CA2/2 and declined under CA2/8. Thus in cv. Hysam, CA storage reduced pungency and flavour by reducing both flavour precursors and enzyme activity.

We also recommend Trading Suppliers and Manufacturers of S-(1-carboxypropyl)cysteine (cas 108203-31-2). Pls Click Website Link as below: cas 108203-31-2 suppliers