No abstract

The small white apricot is a juicy, delicious fruit with a short shelf life. Slight fermentation can significantly promote the flavors and nutrient value of apricot juice. This study used high-performance liquid chromatography (HPLC) and headspace solid-phase microextraction combined with gas chromatography–mass spectrometry (HS-SPME-GC-MS) to examine the physicochemical properties, nutritive value and flavor substances of apricot juice fermented by Lactobacillus plantarum LP56. Fermentation significantly increased lactic acid bacteria (LAB) and their product lactic acid, adding probiotic benefits to fermented apricot juice. In addition, the total phenolic compounds and antioxidant capacity increased, while the levels of soluble solids and organic acids decreased. Gallic acid, 3-caffeoylquinic acid and rutin mainly contributed to the antioxidant activity of fermented apricot juice. Alcohols, aldehyde, acid, ester, etc., were the main volatile compounds. Among the flavors, 12 substances with high odor activity values (OAV > 1) were the key aroma-producing compounds with fruit, pine and citrus flavors. In conclusion, this study shows that L. plantarum LP56 fermentation can improve the nutritional value and aroma characteristics of apricot juice.

Flavor (odor and taste) have a significant role in the consumer’s acceptance, and volatile compounds are responsible for the odor of apricots. In the present work, headspace solid-phase microextraction with gas chromatography coupled to tandem mass spectrometry (HS-SPME-GC-MS/MS) together with multivariate analysis, i.e., partial least square discrimination analysis (PLS-DA), were applied to construct the volatile fingerprints and biomarkers of apricots in Xinjiang, China. As a result, a total of 63 volatile substances were identified in the fruits of four apricot cultivars, seven of which were considered to serve as volatile biomarkers, which are damascenone for Dabaiyou apricots; acetophenone, myrcenol and 7-hexadecenal for Luopuhongdaike apricots; 2,4-dimethyl-cyclohexanol for You apricots; eucalyptol and salicylaldehyde for Xiaobai apricots. Moreover, Xiaobai apricots were richer in soluble sugars, organic acids and total phenolic and total flavonoid content than the other three apricot varieties. This work helps to characterize the volatile profiles and biomarkers of different apricot cultivars while providing theoretical guidance for developing apricot-flavored foods in practical production.