Characterization of the key aroma compounds in Yunnan goat milk cake using a sensory‐directed flavor analysis

Abstract

To identify the key aroma compounds in Yunnan goat milk cake, seven varieties of milk cake samples were subjected to sensory analysis and gas chromatography‐mass spectrometry (GC‐MS), gas chromatography‐olfactometry (GC‐O), aroma recombination, omission, and addition tests. The GC‐MS results revealed 53 compounds with aroma characteristics in all the samples. A further comparison of odor activity values and aroma intensities (AI) revealed 25 of these compounds as the initial key aroma compounds. The contributions of these key aroma compounds to the sensory attributes were determined using a partial least squares regression. Of these compounds, 2‐heptanone and 2‐nonanone were closely related to the “milky” and “cheesy” attributes and were highly abundant in the samples from Kunming. Fatty acids, including butanoic acid, hexanoic acid, octanoic acid, and decanoic acid, were the most abundant compounds detected in the milk cakes. These fatty acids were closely related to the “rancid” and “animalic (goat)” attributes and were largely detected in the samples from Dali Dengchuan and Dali Xiaguan. Sensory‐directed aroma recombination, omission, and addition tests further validated the important contributions of ethyl butyrate, benzaldehyde, 3‐methyl‐1‐butanol, 2‐heptanone, hexanoic acid, and octanoic acid to the overall sensory properties. Moreover, ethyl butyrate, benzaldehyde, and 2‐heptanone, when added, had evident inhibitory or masking effects on the AI of “sour,” “rancid,” and “animalic (goat)” attributes. Practical Application Goat milk cake is a popular acid‐curd cheese in Yunnan, China, however, our limited knowledge to its key aroma compounds restricts its development and industrial production. In this study, a sensory‐directed flavor analysis was used to characterized the key aroma compounds of Yunnan goat milk cake, which will help to enhance our understanding on the flavor profile of Yunnan goat milk cake and provide a reference for optimizing the flavor feature and organoleptic quality of this fresh goat cheese.

Characteristic flavour compounds and formation of Chinese Rubing cheese: Comparative study between two different acidification technologies

“…Tian et al . (2020a) also detected rich fatty acids (5.337 to 13.93 mg/kg) in goat rubing cheese. The above results elucidated that the fermented acidification technology significantly increased the fatty acid types and contents ( P < 0.05), which might be due to the unique acidification technology of FRB.…”

“…It is also prepared by adding naturally fermented sour whey to cattle milk for fast acid-curdling, then heating the milk to around 75 °C, blanching, stretching, forming and drying. Tian et al (2020a) also detected rich fatty acids (5.337 to 13.93 mg/kg) in goat rubing cheese. The above results elucidated that the fermented acidification technology significantly increased the fatty acid types and contents (P < 0.05), which might be due to the unique acidification technology of FRB.…”

Aroma classification and characterization of Lactobacillus delbrueckii subsp. bulgaricus fermented milk

“…Area A consisted of 15 volatile compounds including 5 alcohols, 1 sulfide, 3 aldehydes, 1 easter, 4 ketones, and 1 other compound. Dimethyl disulfide could provide an onion and cabbage flavor for yogurt ( Tian et al, 2020 ), and its concentration in L4-1-2 was higher than that in L6-11, which might cause L4-1-2 had a higher score in cheesy attribute than L6-11. Besides, there were also 3 aldehydes in area A , which came from an amino acid by transamination.…”

“…After extraction, the fiber was inserted into the injector port of GC–MS and desorbed for 6 min at 250 ℃ in splitless mode. The GC–MS analysis was operated using an Agilent 8890 GC/7000D MSD according to Tian et al, 2020 , Dan et al, 2017 with minor modifications. The volatile compounds were determined on a capillary column Agilent HP-INNOWax column (60 m × 0.25 mm, 0.25 μm, Agilent Technologies) and a capillary column Agilent HP-5MS column (30 m × 0.25 mm, 0.25 μm, Agilent Technologies).…”

“…The time of the onset and end of the aroma-active compounds, the perceived odor characteristic, and aroma intensity (AI) were recorded. AI was marked using the 6-point scale from 0 (none detected) to 5 (extremely strong) ( Tian et al, 2020 ). The GC-O-MS analysis was performed in triplicate by each panelist.…”