Formation of volatile compounds in kefir made of goat and sheep milk with high polyunsaturated fatty acid content.
This article explored the formation of volatile compounds during the production of kefir from goat and sheep milks with high polyunsaturated fatty acids (PUFA) as a result of feeding animals forage supplemented with maize dried distillers grains with solubles (DDGS). The increased PUFA content of the goat and sheep milks resulted in significant changes to the fermentation process. In particular, apart from an increase in the time taken to ferment sheep milk, fermentation yielded less 2,3-butanedione. The highest quantities of this compound were assayed in kefir produced from goat milk with an increased content of PUFA. An increase of PUFA significantly elevated ethanal synthesis during lactose-alcohol fermentation of sheep milk. Neither the origin of milk (sheep or goat) nor the level of PUFA had any statistical effect on the amount of ethanal assayed during the fermentation of milk and within the finished product. The proportion of l(+)-lactic acid was higher in kefirs produced using goat milk compared with sheep milk and did not depend on the content of PUFA in milk fat. The content of PUFA had a significant effect on the aroma profile of the resulting kefirs. An increase in PUFA content resulted in the loss of whey aroma in goat milk kefirs and the animal odor in sheep milk kefirs, and a creamy aroma became more prevalent in kefirs made from sheep milk.
Department of Dairy Technology, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 31, 60-624 Poznań, Poland.
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Cais-Sokolińska
Department of Small Mammals Breeding and Raw Material of Animal Origin, Poznań University of Life Sciences, Słoneczna 1, 62-002 Suchy Las, Poland. Electronic address: jacwojto@gmail.com.
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Wójtowski
Department of Dairy Technology, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 31, 60-624 Poznań, Poland.
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Pikul
Department of Dairy Technology, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 31, 60-624 Poznań, Poland.
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Danków
Department of Dairy Technology, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 31, 60-624 Poznań, Poland.
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Majcher
Department of Dairy Technology, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 31, 60-624 Poznań, Poland.
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Teichert
Institute of Genetics and Animal Breeding of the Polish Academy of Sciences in Jastrzębiec, Postępu 36A, 05-552 Magdalenka, Poland.
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Bagnicka
D000821:Animal Feed / Q000032:analysis; D000818:Animals; D043302:Cultured Milk Products / Q000737:chemistry*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D002523:Edible Grain / Q000737:chemistry*; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D005285:Fermentation; D006041:Goats; D007778:Lactobacillus / Q000378:metabolism*; D034561:Sheep, Domestic; D055549:Volatile Organic Compounds / Q000378:metabolism*; D003313:Zea mays
D005231:Fatty Acids, Unsaturated; D055549:Volatile Organic Compounds
fermentation; goat and sheep milk; kefir; polyunsaturated fatty acids; volatile compounds