Kefir Growth in Different Culture Media

Abstract

Kefir is a food supplement of great therapeutic value and also a probiotic food. The purpose of this project was to analyze kefir growth in different culture media. First, kefir grains were placed to grow in sterilized test tubes. The colony of kefir was divided into 16 samples containing from 9.579g to 10.400g of kefir grains. Growth was controlled by weight before and after filtration, and the pH of each solution was measured. After each measurement, the solution was disposed of and exchanged for the same amount and ingredients. These procedures were repeated for 3 consecutive days. After four days, the percentage of Kefir growth obtained in the solutions were at: whole milk (WM): 77%; whole milk with papaya juice (WMP): 64%; whole milk with orange juice (WMO): 34%; whole milk with lemon juice (WML): 72%; reduced fat milk (RFM): 120%; reduced fat milk with papaya juice (RFMP): 111%; reduced fat milk with orange juice (RFMO): 86%; reduced fat milk with lemon juice (RFML): 49%; skimmed milk (SM): 75%; skimmed milk with papaya juice (SMP): 75%; skimmed milk with orange juice(SMO): 93%; skimmed milk with lemon juice (SML): 86%; powdered milk (PM): 71%; powdered milk with papaya juice (PMP) 34%; powdered milk with orange juice (PMO): 39%; powdered milk with lemon juice (PML): 44%. The changed pHs obtained after each filtration of the solutions were: WM from 6.5 to 4; WMP: from 6.5 to 3.5; WMO: from 6 to 3; WML: from 4 to 3.5; RFM: from 6 to 4; RFMP: from 6 to 4; RFMO: from 5 to 3.5; RFML: from 4 to 3.5; SM: from 6.5 to 4; SMP: from 6 to 3.5; SMO: from 5 to 3.5; SML: from 4 to 3; PM: from 7 to 4; PMP: from 6 to 3.5; PMO: from 6 to 3.5; PML: from 3 to 3. The Kefir colony showed more growth in the reduced fat milk, and reduced fat milk with papaya juice, and substantially growth at skimmed milk with orange juice. The fermentation induced the growth of Kefir grains, the production of lactic acid and the decrease of the pH in the solutions. However if pH decreases more than 2 units, it decreases the Kefir growth. It is necessary more studies to evaluate the adequate initial pH to optimizing Kefir growth.Support or Funding InformationThis research was supported by the CECS ‐ Engineering, Modeling and Applied Social Science Department of the Federal University of ABC. Solutions and amount of Kefir grains. SOLUTION'S COMPOSITION AMOUNT INITIAL OF KEFIR (g) T1 WHOLE MILK 10.002 T2 WHOLE MILK + PAPAYA JUICE 10.232 T3 WHOLE MILK + ORANGE JUICE 10.156 T4 WHOLE MILK + LEMON JUICE 9.69 T5 REDUCED FAT MILK 10.4 T6 REDUCED FAT MILK + PAPAYA JUICE 10.4 T7 REDUCED FAT MILK + ORANGE JUICE 9.971 T8 REDUCED FAT MILK + LEMON JUICE 10.077 T9 SKIMMED MILK 9.912 T10 SKIMMED MILK + PAPAYA JUICE 9.992 T11 SKIMMED MILK + ORANGE JUICE 10.329 T12 SKIMMED MILK + LEMON JUICE 10.367 T13 POWDERED MILK 9.875 T14 POWDERED MILK + PAPAYA JUICE 10.153 T15 POWDERED MILK + ORANGE JUICE 9.579 T16 POWDERED MILK + LEMON JUICE 9.782