Pulsed electric fields (PEF) accounts for one of the novel non-thermal processing and preservation technologies and is regarded as an emerging application with the advantage of minimising the loss of valued bioactive compounds in food processing. In this study, various PEF pulses were applied to jujube pulp before fermentation. The fermentation kinetics, compositions, volatile and sensory characteristics were investigated and compared. Results showed that the PEF pretreatment with ten exponential wave pulses at 1.5 kV cm −1 , 1 Hz improved phenolic compounds extraction, especially for caffeic acid, morin and p-hydroxybenzoic acid. Besides, fifty pulses pretreatment enhanced 10% of the wine dry extract. In addition, PEF pretreatment significantly enriched the floral and fruity volatile notes to jujube wine with a decrease in fusel oil. Consequently, PEF preprocessing is a promising method that can be adopted in winemaking industry to promote wine quality and sensory profile.
Binbin Li,Qian Mu,Huijing Guo,Wenting Jia,Mengzhen Zhang,Ya Liu,Xinwen Jin
The effects of jujube pretreatment at different roasting temperatures (80–160 °C) on the dynamic changes in free amino acids and volatile organic compounds in jujube wine were evaluated using HPLC, HS-GC-IMS, HS-SPME-GC–MS, and sensory analysis. The results revealed that roasting at 80–100 °C enhanced the accumulation of sweet amino acids in jujube wine, whereas roasting at 140–160 °C increased the bitter amino acid content. As the roasting temperature increased, the contents of esters, alcohols, acids, aldehydes, and ketones in jujube wine rose initially before declining thereafter. Meanwhile, the furan compound content exhibited a continuous increase. Through multivariate statistical analyses, including orthogonal partial least squares-discriminant analysis (OPLS-DA), relative odor activity value (ROAV) calculations, and variable importance in projection (VIP), six key characteristic flavor compounds were identified. These included isoamyl acetate, ethyl hexanoate, and ethyl octanoate. The novel insights derived from this study could guide the improvement of jujube wine flavor.