title: Fermentation process for production of apple-based kefir vinegar: microbiological, chemical and sensory analysis.
abstract: The aim of this study was to develop a kefir apple-based vinegar and evaluate this fermentation process using new methodology with Biospeckle Laser. Brazilian kefir grains were inoculated in apple must for vinegar production. In this study, the microbial community present in kefir, and correspondent vinegar, was investigated using Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS) technique. Saccharomyces cerevisiae, Lactobacillus paracasei, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii were the microbial species identified. S. cerevisiae, L. plantarum, A. pasteurianus and A. syzygii were found in smaller quantities at the beginning of the alcoholic fermentation, but were found throughout the alcoholic and acetic fermentation. Kefir grains were able to utilize apple must as substrate to produce ethanol, and acetic acid. Acetate, volatile alcohols and aldehydes in the vinegar-based kefir were also produced. The yield of acetic acid in the kefir vinegars was ∼79%. The acetic acid concentration was ∼41gL-1, reaching the required standard for the Brazilian legislation accepts it as vinegar (4.0% acetic acid). Kefir vinegar showed good acceptance in the sensory analysis. The technology proposed here is novel by the application of immobilized-cell biomass (kefir grains) providing a mixed inocula and eliminating the use of centrifuge at the end of the fermentative process. This step will save energy demand and investment. This is the first study to produce apple vinegar using kefir grains.
authors.affiliation: Federal University of Lavras (UFLA), Biology Department, Lavras, MG, Brazil.
authors.forename: Roberta Oliveira
authors.initials: RO
authors.lastname: Viana
authors.affiliation: Federal University of Lavras (UFLA), Biology Department, Lavras, MG, Brazil.
authors.forename: Karina Teixeira
authors.initials: KT
authors.lastname: Magalhães-Guedes
authors.affiliation: Federal University of Lavras (UFLA), Department of Engineering, Lavras, MG, Brazil.
authors.forename: Roberto Alves
authors.initials: RA
authors.lastname: Braga
authors.affiliation: Federal University of Lavras (UFLA), Department of Food Science, Lavras, MG, Brazil.
authors.forename: Disney Ribeiro
authors.initials: DR
authors.lastname: Dias
authors.affiliation: Federal University of Lavras (UFLA), Biology Department, Lavras, MG, Brazil. Electronic address: rschwan@dbi.ufla.br.
authors.forename: Rosane Freitas
authors.initials: RF
authors.lastname: Schwan
mesh_terms: D019342:Acetic Acid / Q000032:analysis / Q000378:metabolism; D000091:Acetobacter / Q000302:isolation & purification / Q000378:metabolism; D000434:Alcoholic Beverages / Q000382:microbiology*; D044822:Biodiversity; D001938:Brazil; D000431:Ethanol / Q000032:analysis / Q000378:metabolism; D005285:Fermentation; D005511:Food Handling; D006801:Humans; D000070716:Kefir / Q000032:analysis* / Q000382:microbiology; D007778:Lactobacillus / Q000302:isolation & purification / Q000378:metabolism; D027845:Malus / Q000378:metabolism / Q000382:microbiology*; D012441:Saccharomyces cerevisiae / Q000302:isolation & purification / Q000378:metabolism; D013649:Taste
chemical_list: D000431:Ethanol; D019342:Acetic Acid
keywords: Apple; Biospeckle Laser; Lactobacillus; MALDI-TOF; Saccharomyces; Vinegar; Yeast