Modulation of aroma compounds in yeast and lactic acid bacterium co‐fermented pork hydrolysates by thermal treatment and addition of aroma precursors (cysteine and xylose)

• Published in: International journal of food science & technology Vol. 57; no. 3; pp. 1824 - 1835
• Main Authors: Li, Xinzhi, Liu, Shao‐Quan
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01.03.2022
• Subjects: Acetic acid; Amino acids; Aroma compounds; Browning; Cysteine; Fermentation; Flavor; Flavors; Food industry; Heat treatment; Heat treatments; Hydrolysates; Isoamyl acetate; Lactic acid; Maillard reaction; Meat; Microorganisms; Pork; pork hydrolysates; Sulfur; Sweet taste; Volatile compounds; Volatiles; Xylose; Yeasts
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/ijfs.15560

Summary The objective of this study was to evaluate the effectiveness of using enzymatic hydrolysis and microbial fermentation coupled with thermal treatment methods in valorising a type of industrially generated meat by‐product: pork trimmings, so as to produce a value‐added meat‐based flavouring. The pork trimmings were first hydrolysed using a protease (Flavourzyme) under optimised conditions and then fermented into liquid hydrolysates with mixed Lactobacillus fermentum and Pichia kluyveri; afterwards, xylose and cysteine were added to the fermented hydrolysates for heat treatment. A characteristic “savoury and roasted‐meat” aroma was produced due to the formation of potent sulphur‐containing volatile compounds such as 2‐furfurylthiol and methionol, though the browning intensity was inhibited due to the presence of cysteine. The thermal treatment did not significantly affect the fruity and sweet‐smelling ester volatiles such as isoamyl acetate and hexyl acetate that resulted from microbial fermentation. The decreases of amino acids and xylose might be due to their active participation in the Maillard reaction. The produced pork hydrolysates that imparted a unique aroma could be applied as a flavour enhancer or seasoning in the food industry. The pork trimmings were first hydrolysed using a protease (Flavourzyme) under optimised conditions, then fermented into liquid hydrolysates with mixed Lactobacillus fermentum and Pichia kluyveri; afterwards, xylose and cysteine were added to the fermented hydrolysates for heat treatment. The fermented and thermal treated pork hydrolysates impart a unique sweet aroma and might be applied as a flavour enhancer or seasoning in the food industry.