• Title/Summary/Keyword: microbiology sensory evaluation

Search Result 53, Processing Time 0.018 seconds

Quality Characteristics of the Simple Preprocessed Food Julienne White Radish and Pear during Storage and Development of a Standard Recipe (단순 가공 식품재료 활용을 위한 혼합무배생채의 저장기간에 따른 품질특성 및 레시피 기준 설정)

  • Park, Ji-Hyun;Baek, Ok-Hee
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.21 no.5
    • /
    • pp.706-712
    • /
    • 2011
  • This study was carried out to investigate the quality characteristics and microbiology of the simple preprocessed food julienne white radish and pear during storage at $4^{\circ}C$ and fordevelopment of a standard recipe. Total aerobic bacteria level were $3.20{\pm}0.08$ log CFU/g in julienne white radish and pear, and $3.00{\pm}0.14$ log CFU/g in julienne white radish (control). Coliform counts were $3.20{\pm}0.08$ log CFU/g in julienne white radish and pear and $1.84{\pm}0.17$ log CFU/g in julienne white radish. Low levels of coliform and total aerobic bacteria were detected. pH values of julienne white radish and pear increased significantly after 3days, whereas that of control increased significantly after 1day. Lightness and redness decreased during storage, whereas yellowness increased significantly during storage. During storage, hardness of julienne white radish and pear decreased after 3days, whereas that of julienne white radish decreased after 5days. According to sensory evaluation, 70% julienne white radish and 30% julienne pear showed higher score in term of taste, harmony of ingredient, harmony of sauce and overall preference. Consequently, 70% julienne white radish and 30% julienne pear was determined to the best formula and a maximum storage period of 3 days was showned to be optimal.

Identification and Fermentation Characteristics of Lactic Acid Bacteria Isolated from Dongchimi as Starter for Radish Juice (무 쥬스 제조를 위한 starter로써 동치미에서 분리한 유산균의 동정 및 발효 특성)

  • Kim, Jung-Hee;Kim, Jong-Il
    • Korean Journal of Microbiology
    • /
    • v.35 no.4
    • /
    • pp.307-314
    • /
    • 1999
  • This study was aimed at the investigation of the possibility of the addition of lactic acid bacteria as "starter"for the preparation of radish juice. Forty strains of lactic acid bacteria were isolated from dongchimi that was fermented by a traditional method. The isolates were assorted into 5groups, Leuconostoc mesenteroides subsp. mesenteroides (J-9), Lacobacillus brevis (J-12), Lactobacillus fermentum (J-7), Lactobacillus sake (J-20), and Lactobacillus plantarum (J-39). Leuconostoc mesenteroides was predominated in the sample of dongchimi with frequency of 52.5%. Each of the strain, which exhibited the beat growth in the species, was selected in the 5species, and investigation of the fermentation characteristcis was carried out. The fermentation were performed for 9 days at 25${\circ}C$ after the inoculation of 0.3% ($10^{6}$ cfu/㎖) to each ultra-filtrated radish juice. The pH, total acidity, content of non-volatile organic acids were examined during the fermentation period. Lactobacillus plantarum showed the highest growth rate and the growth rate of Lactobacillus sake was the lowest. The pH (6.3-6.36) and total acidity (0.09-1.0 %) fo the ultrafiltrated radish juice before fermentation were changed to 3.2-4.3 and 0.65-1.2% after 9days, respectively. The changes of the pH and total acidity were related with the growth of the lactic acid bacteria; the better growth of lactic acid bacteria, the more rapid decrease of pH and increase of the total acidity. when the amount of non-volatile organic acids were estimated during fermentation, citric acid, malic acid, malonic acid, and succinic acid were decreased in all cases. However, the content of lactic acid increased with the progression of fermentation. L. mesenteroides (J-9), L. brevis (J-12) and L. fermentum (J-7) were chosen for the candidates of the starter for the lactic fermentation of radish juice based on the biochemical analysis and sensory evaluation.

  • PDF

Changes in Microbial Counts, Enzyme Activity and Quality of Foxtail Millet Takju Treated with High Hydrostatic Pressure during Storage (초고압 처리한 좁쌀탁주의 저장 중 미생물수, 효소활성 및 품질변화)

  • Lim, Sang-Bin;Jwa, Mi-Kyung;Mok, Chul-Kyoon;Park, Young-Seo;Woo, Gun-Jo
    • Korean Journal of Food Science and Technology
    • /
    • v.36 no.2
    • /
    • pp.233-238
    • /
    • 2004
  • Foxtail Millet Takju was treated with heat ($65^{\circ}C/30\;min$) (HT) or high hydrostatic pressure ($27^{\circ}C/400\;MPa/10\;min$) (PT), and changes in microbial count, enzyme activity, and quality were determined during 30-day storage at 10 and $25^{\circ}C$. Total viable cellcount remained constant, while lactic acid bacteria and yeast were not detected in HT and PT Takjus. Relative activities of ${\alpha}-amylase$ in PT Takju significantly increased by 169.7% at 3 days storage, then decreased to 137.7 and 68.7% at 10 and $25^{\circ}C$, respectively, at 30 days. Relative activities of glucoamylase in HT Takju showed reversible change, and were 36.5 and 54.3% at $10\;and\;25^{\circ}C$, respectively, at 30 days storage. Activities in PT Takju increased with storage period, 158.2% at 30 days storage at $10^{\circ}C$. Titratable acidity in untreated Takju increased, while those in HT and PT Takjus remained almost constant during 30 days storage. Reducing sugar content in untreated Takju showed no change, while that in HT Takju increased gradually, reaching 2.9% at 30 days, whereas that in PT increased sharply after 3 days, reaching 4.8% at 30 days. Sensory evaluation showed sourness and bitterness were low, and sweetness and overall acceptance were high in PT Takju after 30 days storage at $10^{\circ}C$.