Characterization of aroma profile and characteristic aromas during lychee wine fermentation

Abstract

Characteristic aroma substances of cis‐rose oxide imparts the odorant of “lychee‐like,” while of citronellol is the precursor of it in lychee. The characterization of volatiles of lychee wine fermentation using headspace solid‐phase microextraction gas chromatography‐mass spectrometry combined with headspace gas chromatography‐ion mobility spectrometry were done to regulate processing. Results indicated that the total of 97 volatiles (38 in common) were observed during fermentation, including 39 terpenoids, 5 alcohols, 22 esters, 4 acids, 7 alkenes, 4 ketones and ethers, 3 sulfur compounds and others. Losses of characteristic aromas mainly occurred during primary fermentation more than threefold decrease. The volatility of cis‐rose oxide was stronger than citronellol, which implied that more gentle processing should be performed to protect lychee flavor. Cis‐rose oxide was a mixture of monomer and dimer with unequal proportion, while citronellol was a monomer in lychee. The work provides important new information on aroma development during fermentation. Practical applications Fruit consumption, among which tropical fruit‐based products have gained huge popularity in the recent years. The main high value‐added processed products of lychee pulp are lychee wine and vinegar; however, the typical aroma always decreased or disappeared during fermentation. Therefore, this study aims at providing more information for product improvement and process development.

Characterization of volatile aroma compounds in litchi (Heiye) wine and distilled spirit

“…1‐octen‐3‐ol presenting OAV >1 was only found in litchi wine (Table 3 ), which is different from the study of Tang et al. ( 2019 ), who did not find 1‐octen‐3‐ol in litchi (Huaizhi) wine.…”

“…The concentration of total acids ranged from 446.59 (litchi juice) to 19058.24 µg/L (litchi distilled spirit) (Figure 2 ). Higher concentrations of octanoic acid (964.80 ± 81.21 µg/L) and decanoic acid (993.17 ± 100.78 µg/L) were recorded in litchi wine (Table 2 ); these values were higher than the values reported previously in lychee wine (319.58 ± 9.33 µg/L and 56.74 ± 0.87 µg/L) (Tang et al., 2019 ), but they were much lower than the amount at the end of alcohol fermentation of litchi wine (8,339.0 ± 794.2 µg/L and 10,711.9 ± 3,499.5 µg/L) (Wu et al., 2011 ). The apparent discrepancy may reflect differences in the type of raw litchi or the fermentation process's duration.…”

“…Tang et al. ( 2019 ) observed a total of 97 volatiles (38 in common) in lychee wine during fermentation, including 39 terpenoids, 5 alcohols, 22 esters, 4 acids, 7 alkenes, 4 ketones and ethers, 3 sulfur compounds, and others. Chen and Liu ( 2016 ) found 84 volatiles and 88 volatiles in the AF (alcoholic fermentation) and MLF (malolactic fermentation) litchi wines, respectively.…”

Non-Targeted Screening Approaches for Profiling of Volatile Organic Compounds Based on Gas Chromatography-Ion Mobility Spectroscopy (GC-IMS) and Machine Learning

“…Due to the complexity of biological matrices, the substance identification with GC-IMS data alone can be challenging, which is why stand-alone IMS are rarely used to investigate the sample composition. Complementary techniques, such as GC-MS [129] or 1 H NMR [130], are often used to identify decisive marker substances [131].…”

Ion Mobility Spectrometry in Food Analysis: Principles, Current Applications and Future Trends

“…In comparison to traditional methods, the use of GC–IMS for their determination allows decreasing the analysis time from 3 h to 10 min [5]. GC-IMS has also been applied to the characterization of VOCs fraction during the fermentation of lychee beverages [73] and wine [74]. One of the advantages of GC–IMS over other analytical tools is that it enables online monitoring and control of bioprocesses [74].…”