title: The evaluation of kefir pure culture starter: Liquid-core capsule entrapping microorganisms isolated from kefir grains.
abstract: The main purpose of this study was to develop a pure culture starter for producing kefir. In order to accomplish starter recycling, yeasts (Kluyveromyces marxianus strain, Pichia kudriavzevii clone), lactic acid bacteria (Lactobacillus kefiri strain F4Aa, Lactobacillus kefiri strain NM131-7, Lactobacillus kefiri strain NM132-3, Lactobacillus kefiri strain NM180-3, respectively), and acetic acid bacteria (Acetobacter lovaniensis strain) were entrapped in liquid core capsules based on the distribution ratio in kefir grains. The microbiological, antimicrobial, and chemical properties of kefir made with capsules (M) and kefir grains (K) were measured and compared. According to the results of plate counts in different selective medium, the number of yeasts and bacteria in the liquid core capsules gradually increased and stabilized after eight fermentation cycles. The results of gas chromatography-mass spectrometry showed that almost all the aroma components existed in the two type of kefir, except the ethyl lactate. There was no significant difference in alcohol content, protein content, and fat content, except the acidity and sugar content. Water holding capacity of kefir K was higher than kefir M. There were 14 same free amino acids in kefir M and kefir K, and the content of most free amino acids was similar. In antimicrobial test, there was no significant difference in both kefirs.
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Jiangsu, P. R. China wangliang_2004wl@163.com.
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Jiangsu, P. R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhong
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Jiangsu, P. R. China.
authors.forename: Keying
authors.initials: K
authors.lastname: Liu
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Jiangsu, P. R. China.
authors.forename: Aizhen
authors.initials: A
authors.lastname: Guo
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Jiangsu, P. R. China.
authors.forename: Xianghui
authors.initials: X
authors.lastname: Qi
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Jiangsu, P. R. China.
authors.forename: Meihong
authors.initials: M
authors.lastname: Cai
mesh_terms: D000091:Acetobacter / Q000145:classification / Q000302:isolation & purification; D000596:Amino Acids / Q000032:analysis; D000890:Anti-Infective Agents / Q000032:analysis; D002214:Capsules / Q000737:chemistry; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification; D005285:Fermentation; D005506:Food Contamination / Q000517:prevention & control; D005511:Food Handling; D005516:Food Microbiology; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D000070716:Kefir / Q000382:microbiology*; D007716:Kluyveromyces / Q000145:classification / Q000302:isolation & purification; D007778:Lactobacillus / Q000145:classification / Q000302:isolation & purification; D010843:Pichia / Q000145:classification / Q000302:isolation & purification; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D000596:Amino Acids; D000890:Anti-Infective Agents; D002214:Capsules; D055549:Volatile Organic Compounds
keywords: Liquid core capsule; antimicrobial activity; free amino acid; kefir; volatile aroma compounds