scholarly journals Optimization of lactic acid bacteria viability using fuzzy soft set modelling

Author(s):  
Reyhan Irkin ◽  
Nihal Yilmaz Ozgur ◽  
Nihal Tas

Lactic acid fermented vegetables are important sources of vitamins and minerals. In recent years consumers demand for non-dairy based functional products has increased. Cabbage pickle has high enough concentrations of fiber and also it may show health effect with the containing high numbers of lactic acid bacteria. The aim of this study is to optimize mathematically cabbage-carrot pickle fermentation for the viability of Lactobacillus acidophilus, Lactobacillus casei cultures and the sensory scores in brine with 5% and 7% (w/v) salt concentrations. Viability optimization of lactic acid bacteria is done via the notion of “fuzzy soft set” method. Lb. casei, Lb. acidophilus, total lactic acid bacteria, Enterobacteriaceae sp., yeast-mould counts and pH values have been reported during the 30 days of storage. The results are compared with the control traditional fermented cabbage-carrot pickle. Organoleptic properties are evaluated. We conclude that the fermented pickle samples contain a significant number of beneficial lactic acid bacteria and high sensory marks at the end of the storage.

Author(s):  
M. Raveendra Reddy ◽  
P. Jayamma ◽  
V. Srilatha

Background: Sapota (Achras sapota L. or Manilkara zapota L.) is one of the major fruit crops grown in subtropical countries and it contains sugars, acids, protein, phenolics carotenoids, ascorbic acid, minerals and vitamins. Growing of lactic acid bacteria in fruit juices for health benefits and improving the nutritional and sensory attributes of the fruit juice is becoming more prominent in the present days. In recent years, consumer preference for non dairy food products has increased especially for lactose intolerance people. The present study is aimed to develop probioticated sapota fruit juice using probiotic bacteria like Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus casei. Methods: Sapota fruit juice was prepared and inoculated with four different species of proven probiotic lactic acid bacteria (Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus acidophilus and Lactobacillus casei) and incubated at 30oC and 37oC for 72 hours. Population dynamics of lactic acid bacteria and their impact on physicochemical properties of probiotic sapota juice during fermentation at two different temperatures were studied. Sensory evaluation was also studied to know the overall acceptability of the probiotic fruit juice. Result: The pH decreased and titratable acidity (TA) increased in all probiotic sapota juice samples incubated at 30oC and 37oC for 72 hours and the maximum titratable acidity was recorded by T4 (Lactobacillus plantarum) followed by T1 (L. acidophilus). All the three carbohydrates like glucose, fructose and sucrose present in sapota juice samples were utilized by the lactic acid bacteria during fermentation. Total phenolic concentration in the samples increased during fermentation. Viable cell counts in both samples kept at 30oC and 37oC gradually increased from 0 to 48 hours and then decreased. Sensory evaluation was conducted randomly for all the samples and no significant difference was recorded.


2021 ◽  
Vol 9 (5) ◽  
pp. 1044
Author(s):  
Jeong A Kim ◽  
Geun Su Kim ◽  
Se Mi Choi ◽  
Myeong Seon Kim ◽  
Do Young Kwon ◽  
...  

Hardening of cheese is one of major issues that degrade the quality of Home Meal Replacement (HMR) foods containing cheese such as Cheese-ddukbokki rice cake (CD, stir-fried rice cakes with shredded cheese). The quality of cheese, such as pH, proteolytic, and flavor properties, depends on various lactic acid bacteria (LAB) used in cheese fermentation. The hardening of cheese is also caused by LAB. In this study, various LAB strains were isolated from CD samples that showed rapid hardening. The correlation of LAB with the hardening of cheese was investigated. Seven of the CD samples with different manufacturing dates were collected and tested for hardening properties of cheese. Among them, strong-hardening of cheese was confirmed for two samples and weak-hardening was confirmed for one sample. All LAB in two strong-hardening samples and 40% of LAB in one weak-hardening sample were identified as Latilactobacillus curvatus. On the other hand, most LAB in normal cheese samples were identified as Leuconostoc mesenteroides and Lactobacillus casei. We prepared cheese samples in which L. curvatus (LC-CD) and L. mesenteroides (LM-CD) were most dominant, respectively. Each CD made of the prepared cheese was subjected to quality test for 50 days at 10 °C. Hardening of cheese with LC-CD dominant appeared at 30 days. However, hardening of cheese with LM-CD dominant did not appear until 50 days. The pH of the LC-CD was 5.18 ± 0.04 at 30 days, lower than that of LM-CD. The proteolytic activity of LC-CD sample was 2993.67 ± 246.17 units/g, higher than that of LM-CD sample (1421.67 ± 174.5 units/g). These results indicate that high acid production and high protease activity of L. curvatus might have caused hardening of cheese.


1970 ◽  
Vol 37 (1) ◽  
pp. 17-28 ◽  
Author(s):  
T. F. Fryer ◽  
M. Elisabeth Sharpe ◽  
B. Reiter

SummaryA study was made of the utilization of citrate in milk by some lactic acid bacteria. WhenStreptococcus diacetilactis1007 was grown alone or with eitherStreptococcus cremoris924 orLactobacillus caseiB 142/C or with both these latter organisms, > 99% of the milk citrate was utilized within 5 days.L. caseiB 142/C andL. casei/Str. cremorisutilized 57 and 14% of the citrate, respectively. WhenL. caseiC 2 andL. caseiC 5 were grown in milk in whichStr. cremoris924 had been previously grown, 94 and 64%, respectively, of the citrate was utilized after 7 days at 30°C.Cheeses were made using a citrate-fermenting and a non-citrate-fermenting starter and citrate concentrations of the milks, wheys and curds were determined during cheese-making. WithStr. cremoris924, citrate was preferentially retained in the curd at pressing, the concentration in the curd moisture being 2·9 times that in the whey. With the mixed starterStr. cremoris924/Str. diacetilactis1007, the curd at pressing and from the press contained only 27 and 5%, respectively, of the citrate present in theStr. cremoriscurd at these times.Cheeses were made usingStr. cremoris924, combinations ofStr. cremoris/Str. diacetilactis1007, or with δ-gluconic acid lactone instead of starter, with and without the addition ofL. caseiC 5, in order to examine the ability of the latter organism to produce ‘blowing’ in the sense of distension of the Cryovac wrapping of film-wrapped cheeses.L. caseiC 5 neither accelerated the decrease in cheese citrate nor produced blowing of the film-wrapping. Possible reasons for this behaviour are discussed.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mariya Dushkova ◽  
Siyka Kodinova ◽  
Zapryana Denkova ◽  
Velichka Yanakieva ◽  
Nikolay Dimitrov Menkov

Abstract The purpose of this study was to investigate the microbiological (number of viable lactic acid bacteria and bifidobacteria), physicochemical (dry matter, protein and fat contents, titratable acidity, and pH), and sensory characteristics (appearance of coagulum, taste and aroma, structure at cutting, color, and consistency at shattering) of probiotic Bulgarian yoghurts obtained by ultrafiltration of goat’s milk. These yoghurts were obtained using volume reduction ratios of 2 and 3 with the probiotic starters MZ2f, MZ2f + Bifidobacterium bifidum BB – 87, and MZ2f + Lactobacillus acidophilus LAB – 8. The increase in the level of the concentration by ultrafiltration led to an increase in the dry matter, protein and fat contents of the yoghurts, in the number of lactic acid bacteria and titratable acidity, and to a decrease in the pH. The twofold concentration by ultrafiltration resulted in a higher number of lactic acid bacteria in comparison with yoghurts made without ultrafiltration, and with better sensory characteristics compared to yoghurts without and with threefold ultrafiltration. The higher number of viable cells and better sensory characteristics were obtained for yoghurts with MZ2f + Bifidobacterium bifidum BB – 87 and MZ2f + Lactobacillus acidophilus LAB – 8 in comparison with MZ2f alone.


1971 ◽  
Vol 34 (11) ◽  
pp. 521-525 ◽  
Author(s):  
J. R. Stamer ◽  
B. O. Stoyla ◽  
B. A. Dunckel

The effects of pH values and NaCl concentrations on the growth rates of five species of lactic acid bacteria commonly associated with the sauerkraut fermentation were determined in filter-sterilized cabbage juice. Growth rates of all cultures, with the exception of Pediococcus cerevisiae, were retarded by addition of salt, lower pH, or interaction of both pH and salt. Based upon lag and generation times, P. cerevisiae was the culture most tolerant to the pH and salt concentration employed, whereas Streptococcus faecalis was the most sensitive species. Of the heterofermentative cultures, Lactobacillus brevis was less subject to growth inhibition than Leuconostoc mesenteroides. Under conditions simulating those found during the initial phases of the sauerkraut fermentation (2.25% salt, pH 6.2), L. mesenteroides displayed the shortest lag and generation times of all cultures examined. This rapid growth rate coupled with a marked accelerated death rate may explain, in part, the reason this species is both the first to dominate and the first to die during the early phases of the sauerkraut fermentation. Although cabbage juice previously fermented by L. mesenteroides appears to inhibit growth of P. cerevisiae, it had no apparent inhibitory or stimulatory effects on the other cultures.


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