Volatile organic compounds profiles in milk fermented by lactic bacteria

Abstract

The organoleptic properties of traditional dairy beverages done with non-conventional dairy species (horse, camel), popular in Central Asia, were rarely described in the literature. To characterize the Volatile Organic Compounds (VOC) profile of fermented mare milk, 12 samples of cow milk, used as matrix were inoculated by different strains from two types of bacteria (bacilli and cocci) isolated from natural fermented mare milk. The analysis performed by Gas Chromatography coupled with Solid-Phase Micro-Extraction allowed identification of 160 different compounds from the 12 strains, and 90 from natural fermented mare milk. After cluster analysis, 3 types of profiles were observed. Those profiles were distinct by the amount of acid compounds (low, medium, high), negatively related to aromatic and aliphatic hydrocarbons. The analysis of the mean volatile compound profile of each type of bacteria (bacilli and cocci) by factorial discriminant analysis showed that 3 molecules (oxime-methoxy-phenyl, propanedioic acid propyl and 2-propanamine) allowed to well class 100% of the samples. Further researches on bacterial identification and experiments with different fermentation matrices from other dairy species will be conducted.

Fermentation Enhanced Biotransformation of Compounds in the Kernel of Chrysophyllum albidum

“…One intermediate (I-1), a primary α-hydroxy ketone with butan-2-one substituted by a hydroxy group at positions 1 and 3 or a secondary α-hydroxy ketone, has a close structural analogue of 3,4-dihydroxybutan-2-one, whose phosphorylated form ( l -3,4-dihydroxybutan-2-one 4-phosphate) is a precursor for the synthesis of riboflavin [ 47 ]. Formyl 7 E -hexadecenoate, an effective nitrogen removal stimulant found in aquatic duckweed, was reported in lactic acid bacteria enhanced fermented milk [ 48 , 49 ]. Methyl petroselinate (C5) was also previously detected as fermented products of Korean red pepper and the extract of miswak plant, Salvadora persica L [ 50 , 51 ].…”

Fermented mare milk product (Qymyz, Koumiss)

“…Mare milk undergoes two-step fermentation -lactic fermentation and alcoholic fermentation. The final products of these fermentations are lactic acid, ethyl alcohol, carbon dioxide and other by-products such as volatile acids, fusel alcohols, and other compounds with a strong and distinctive aroma and taste (Fuquay et al, 2011;Kondybayev et al, 2018). In 1858 N.V. Postnikov, a Russian doctor, discovered the effectiveness of the use of sour mare's milk in the treatment of patients with pulmonary tuberculosis and decided to introduce the use of qymyz into medical practice by opening a 'qymyz' hospital near Samara, Russia.…”