No abstract

Peony (Paeonia section Moutan DC.) seed oil is a novel vegetable oil with unique aromatic profile. The objectives of this study were to characterize the volatile compounds with optimized analysis conditions, and to study the effects of oxidation during storage. The Headspace Solid-phase Micro-extraction (HS-SPME) conditions were optimized with factors including extraction fiber, extraction time and temperature, as well as sample amount and desorption time. Then, the aromatic compounds extracted from peony seed oil were determined using the odor activity value (OAV) method coupled with the GC-olfactometry. Results found that the best HS-SPME conditions were DVB/CAR/PDMS fibers with magnetic stirring for 50 min of extraction at 60 • C. The optimal sample amount was 4 g with 6 min of desorption. Forty-one volatile components were found, and 19 aromatic components were identified using GC-MS and GC-olfactometry. This is the first study to describe 4,7-dimethylbenzofuran in peony seed oil with a unique aroma of grass, light bitter, and fragrance. The stability of alcohol and terpenoids decreased as accelerated oxidation progresses. This study provides the theoretical basis for the sensory attributes, and shelf-life of peony seeds oil products for industry production and marketing.

Sichuan pickle represents the traditional fermented vegetables in China, and it forms the characteristic Sichuan cuisine that is known worldwide. The spontaneous or semi-spontaneous fermentation processes of pickles are hard to control. However, pickle production cannot be fully controlled, and nearly 5% of pickle production goes to waste. Nearly 200,000 tons of pickle products are deteriorated in China, resulting in more than 150 million USD yearly economic losses. Among the quality deterioration of Sichuan pickles, the formation of white membranes on the surface of pickles is the most common phenomenon (Feng et al., 2018). White membrane forms