scholarly journals Storage stability of freeze-dried Lactobacillus plantarum S20 starter culture as affected by various formulations of drying medium, and its fermentation characteristics in mung bean (Vigna radiata L.) slurry was studied by Sulabo et al.

Food Research ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 964-975
Author(s):  
A.S.L. Sulabo ◽  
M.E.L. Villasanta ◽  
K.G. Hermo ◽  
R.A. Lascano ◽  
L.S. Collado ◽  
...  

Development of an active starter culture is essential in the production of safe and highquality fermented foods. Freeze-drying is an effective microbial cell immobilization technology intended to produce active and stable starter cultures for long-term storage. To determine the influence of various drying medium formulations with mung bean powder and disaccharides on the viability of L. plantarum S20 during freeze-drying and subsequent storage at 6±2°C and 30±1°C, three treatments of drying medium consisting of mung bean powder without disaccharides (MBP), MBP with 5% (w/v) trehalose (MBP+T), and MBP with 5% (w/v) sucrose (MBP+T) were evaluated. Results showed that L. plantarum S20 viability after freeze-drying ranged from 9.56 to 10.03 log (CFU/g) with viability loss ranging from 0.20 to 0.51 log (CFU/g), with MBP being the least effective (p<0.05) in minimizing viability loss. Supplementing MBP with either 5% sucrose or 5% trehalose improved (p<0.05) survival of freeze-dried L. plantarum S20; and both disaccharides exhibit similar (p>0.05) cryoprotective effects on L. plantarum S20 during freeze-drying and subsequent storage. Storage at 6±2°C for 180 days resulted in significant decreases of 2.15, 2.17, and 3.27 log (CFU/g) in L. plantarum S20 population in MBP+T, MBP+S, and MBP, respectively. A more drastic decline [>6.0 Log (CFU/g)] in L. plantarum S20 population was observed in freeze-dried culture stored at 30±1°C for 60 days. Fermentation characteristics of freeze-dried L. plantarum S20 in mung bean slurry were also determined. Freeze-dried L. plantarum S20 in MBP with 5% (w/v) sucrose was able to acidify mung bean slurry from pH 6.8 to pH 3.8 after 8 hrs with maximum LAB population of 9.2 log (CFU/mL). Acidification of mung bean slurry by fresh culture (non-freeze-dried) on the other hand was relatively slower where pH dropped from 6.8 to pH 3.72 after 24 hrs. Current work suggested that lyophilized L. plantarum S20 could be used as a starter culture for mung bean-based fermentations but further research on this area is needed.

2010 ◽  
Author(s):  
◽  
Vinodh Aroon Edward

Cassava, (Manihot esculenta Crantz), is used for the production of a variety of West African foods and ranks fourth in the list of major crops in developing countries after rice, wheat and maize. Gari is one of the most popular foods produced from cassava. Cassava may contain high levels of linamarin, a cyanogenic glucoside, which in its natural state is toxic to man. Therefore, some processing methods that can enhance the detoxification of cassava and lead to the improvement of the quality and hygienic safety of the food are vitally important for less toxic products to be obtained. Quality, safety and acceptability of traditional fermented foods may be improved through the use of starter cultures. There has been a trend recently to isolate wild-type strains from traditional products for use as starter cultures in food fermentation. A total of 74 bacterial strains and 21 yeast strains were isolated from a cassava mash fermentation process in a rural village in Benin, West Africa. These strains were assessed, together with 26 strains isolated at the CSIR from cassava samples sent from Benin previously, for phenotypic and technological properties. Twenty four presumptive lactic acid bacteria (LAB) were selected for further phenotypic, genotypic and technological characterization during a research visit to the BFE (now Max Rubner Institute of Nutrition and Food). After assessment, the strains VE 20, VE 36, VE 65b, VE 77 and VE 82 were chosen for further study as starter cultures. These L. plantarum strains were chosen on the basis of predominance and possession of suitable technological properties. The investigation of this study was complemented by further, similar studies on further Gari isolates in Germany by the BFE. That study was done independently from this study, but both studies served to select potential starter cultures for cassava fermentation for the production of Gari, as this was the common goal of the project. Thus, a wider final selection of potential starter cultures was decided on at the project level and this selection was further tested in fermentation experiments. A total of 17 strains were grown in optimized media in 2 L fermenters. These strains were freeze-dried and thereafter tested in lab-scale cassava mash fermentation trials. xiii The strains performed well in the small scale bucket fermentations. There was a rapid acidification evidenced by the increase in titratable acidity, ranging from 1.1 to 1.3 % at 24 hours, and 1.3 to 1.6 % at 48 hours. The effect of the starter was obvious in that it lowered the pH much faster and to lower levels than the control. It appeared that both the processing and starter culture addition played a role in the removal of cyanide during processing of the cassava into Gari. This was evident from the lower cyanide values obtained for fermentations that included starter cultures. The study also showed that especially the L. plantarum group strains could be produced as starter cultures at lower costs than compared to L. fermentum, W. paramesenteroides or L. mesenteroides strains. Overall the results of this study were crucial for the project in showing that a starter culture which is easy and economical to produce and which has the desired attributes is a feasible possibility for application in the field.


2015 ◽  
Vol 6 (3) ◽  
pp. 381-386 ◽  
Author(s):  
A. Jofré ◽  
T. Aymerich ◽  
M. Garriga

The production of long shelf-life highly concentrated dried probiotic/starter cultures is of paramount importance for the food industry. The aim of the present study was to evaluate the protective effect of glucose, lactose, trehalose, and skim milk applied alone or combined upon the survival of potentially probiotic Lactobacillus rhamnosus CTC1679, Lactobacillus casei/paracasei CTC1677 and L. casei/paracasei CTC1678 during freeze-drying and after 39 weeks of storage at 4 and 22 °C. Immediately after freeze-drying, the percentage of survivors was very high (≥94%) and only slight differences were observed among strains and cryoprotectants. In contrast, during storage, survival in the dried state depended on the cryoprotectant, temperature and strain. For all the protectants assayed, the stability of the cultures was remarkably higher when stored under refrigeration (4 °C). Under these conditions, skim milk alone or supplemented with trehalose or lactose showed the best performance (reductions ≤0.9 log units after 39 weeks of storage). The lowest survival was observed during non-refrigerated storage and with glucose and glucose plus milk; no viable cells left at the end of the storage period. Thus, freeze-drying in the presence of appropriate cryoprotectants allows the production of long shelf-life highly concentrated dried cultures ready for incorporation in high numbers into food products as starter/potential probiotic cultures.


1970 ◽  
Vol 68 (1) ◽  
pp. 29-41 ◽  
Author(s):  
Masatoshi Suzuki

SummaryUnpurified and purified smallpox vaccines were prepared from calf dermal pulp, or chorioallantoic membrane (CAM) of hen eggs infected with vaccinia virus, and freeze-dried. The protective effect of various suspending media was investigated both in the course of the freeze-drying and in the period of subsequent storage of the dried product at different temperatures, including 100° C.Single media consisting of either sodium glutamate or peptone were effective in the preservation of both unpurified and purified vaccines prepared from calf dermal pulp or CAM. It was shown that there was an optimal concentration of sodium glutamate for the preservation of the vaccine preparations, especially of the purified vaccine.Combined media, consisting of soluble starch, polyvinylpyrrolidone or sodium carboxymethyl cellulose with sodium glutamate, were effective with the purified vaccine when the concentration of sodium glutamate exceeded the optimum necessary for preservation.


2019 ◽  
Vol 8 (3) ◽  
pp. 103
Author(s):  
Calvince Anino ◽  
Arnold Onyango ◽  
Samuel Imathiu ◽  
Julius Maina

Fermented foods have in recent times attracted consumer interest mainly due to perceived health benefits of probiotic microorganisms. This study characterized changes in the concentrations of selected B-complex vitamins and oligosaccharides of common bean milk during fermentation by a common dairy starter culture, YF L-903 (Streptococcus thermophilus + Lactobacillus Bulgaricus subs Debulgaricus), and three probiotic cultures namely ABT (Lactobacillus acidophilus La-5 + Bifidobacterium animalis Bb-12 + Streptococcus thermophilus), Yoba (Lactobacillus rhamnosus yoba + Streptococcus thermophilus), and Yoba Fiti (Lactobacillus rhamnosus GR1 + Streptococcus thermophilus). Bean milk was prepared from three common bean varieties. It was found that, apart from thiamine (vitamin B1) and riboflavin (vitamin B2), fermentation with each of the mixed cultures caused significant increase in the vitamin B complex. Significant reductions (p&lt;0.05) in the oligosaccharides concentration of the bean milks were observed upon fermentation. Highest reduction in the oligosaccharide sugars of 77.8% was found in milk from pinto bean variety fermented with ABT culture. These findings suggest that LAB probiotic cultures have a potential for improving biosynthesis of vitamins and removal of the verbascose, stachyose and raffinose oligosaccharides, thus making the product more digestible and the nutrients more bioavailable.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aurore Bodzen ◽  
Audrey Jossier ◽  
Sébastien Dupont ◽  
Pierre-Yves Mousset ◽  
Laurent Beney ◽  
...  

Abstract Background Stabilization of freeze-dried lactic acid bacteria during long-term storage is challenging for the food industry. Water activity of the lyophilizates is clearly related to the water availability and maintaining a low aw during storage allows to increase bacteria viability. The aim of this study was to achieve a low water activity after freeze-drying and subsequently during long-term storage through the design of a lyoprotectant. Indeed, for the same water content as sucrose (commonly used lyoprotectant), water activity is lower for some components such as whey, micellar casein or inulin. We hypothesized that the addition of these components in a lyoprotectant, with a higher bound water content than sucrose would improve lactobacilli strains survival to long-term storage. Therefore, in this study, 5% whey (w/v), 5% micellar casein (w/v) or 5% inulin (w/v) were added to a 5% sucrose solution (w/v) and compared with a lyoprotectant only composed of 5% sucrose (w/v). Protective effect of the four lyoprotectants was assessed measuring Lactiplantibacillus plantarum CNCM I-4459 survival and water activity after freeze-drying and during 9 months storage at 25 °C. Results The addition whey and inulin were not effective in increasing Lactiplantibacillus plantarum CNCM I-4459 survival to long-term-storage (4 log reduction at 9 months storage). However, the addition of micellar casein to sucrose increased drastically the protective effect of the lyoprotectant (3.6 log i.e. 0.4 log reduction at 9 months storage). Comparing to a lyoprotectant containing whey or inulin, a lyoprotectant containing micellar casein resulted in a lower water activity after freeze-drying and its maintenance during storage (0.13 ± 0.05). Conclusions The addition of micellar casein to a sucrose solution, contrary to the addition of whey and inulin, resulted in a higher bacterial viability to long-term storage. Indeed, for the same water content as the others lyoprotectants, a significant lower water activity was obtained with micellar casein during storage. Probably due to high bound water content of micellar casein, less water could be available for chemical degradation reactions, responsible for bacterial damages during long-term storage. Therefore, the addition of this component to a sucrose solution could be an effective strategy for dried bacteria stabilization during long-term storage.


2020 ◽  
Vol 8 (10) ◽  
pp. 1534
Author(s):  
Andrea Comasio ◽  
Simon Van Kerrebroeck ◽  
Henning Harth ◽  
Fabienne Verté ◽  
Luc De Vuyst

Microbial strains for starter culture-initiated sourdough productions are commonly isolated from a fermenting flour–water mixture. Yet, starter culture strains isolated from matrices other than sourdoughs could provide the dough with interesting metabolic properties and hence change the organoleptic properties of the concomitant breads. Furthermore, the selection of sourdough starter cultures does not need to be limited to lactic acid bacteria (LAB), as other food-grade microorganisms are sometimes found in sourdoughs. Therefore, different strains belonging to LAB, acetic acid bacteria (AAB), and coagulase-negative staphylococci (CNS) that originated from different fermented food matrices (fermenting cocoa pulp-bean mass, fermented sausage, and water kefir), were examined as to their prevalence in a wheat sourdough ecosystem during 72-h fermentations. Limosilactobacillus fermentum IMDO 222 (fermented cocoa pulp-bean mass isolate) and Latilactobacillus sakei CTC 494 (fermented sausage isolate) seemed to be promising candidates as sourdough starter culture strains, as were the AAB strains Acetobacter pasteurianus IMDO 386B and Gluconobacter oxydans IMDO A845 (both isolated from fermented cocoa pulp-bean mass), due to their competitiveness in the wheat flour-water mixtures. Wheat breads made with G. oxydans IMDO A845 sourdoughs were significantly darker than reference wheat breads.


Author(s):  
Juan García-Díez ◽  
Cristina Saraiva

Starter cultures can be defined as preparations with a large number of cells that include a single type or a mixture of two or more microorganisms that are added to foods in order to take advantage of the compounds or products derived from their metabolism or enzymatic activity. In foods from animal origin, starter cultures are widely used in the dairy industry for cheese, yogurt and other fermented dairy products, in the meat industry, mainly for sausage manufacture, and in the fishery industry for fermented fish products. Usually, microorganisms selected as starter culture are isolated from the native microbiota of traditional products since they are well adapted to the environmental conditions of food processing and are responsible to confer specific appearance, texture, aroma and flavour characteristics. The main function of starter cultures used in food from animal origin, mainly represented by lactic acid bacteria, consists in the rapid production of lactic acid, which causes a reduction in pH, inhibiting the growth of pathogenic and spoilage microorganisms, increasing the shelf-life of fermented foods. Also, production of other metabolites (e.g., lactic acid, acetic acid, propionic acid, benzoic acid, hydrogen peroxide or bacteriocins) improves the safety of foods. Since starter cultures have become the predominant microbiota, it allows food processors to control the fermentation processes, excluding the undesirable flora and decreasing hygienic and manufacturing risks due to deficiencies of microbial origin. Also, stater cultures play an important role in the chemical safety of fermented foods by reduction of biogenic amine and polycyclic aromatic hydrocarbons contents. The present review discusses how starter cultures contribute to improve the microbiological and chemical safety in products of animal origin, namely meat, dairy and fishery products.


Author(s):  
SungHoo Jegal ◽  
BCIT School of Health Sciences, Environmental Health ◽  
Helen Heacock ◽  
Aljosa Trmcic ◽  
Fred Shaw

  Background: Many comprising studies showed that probiotics can manifest antimicrobial activity. Due to positive health effects of probiotics, they have been added in a fermentation of various foods to increase the nutrient content and to improve the quality of the foods. Furthermore, probiotics are used as a starter culture for several fermented foods like a yogurt. Probiotics may contain strains that are capable of initiating fermentation of the foods, however, a safety of the foods is not certain. Therefore, the study is done to analyze use of probiotics as a starter culture for a yogurt. Methods: The study was designed to analyze the pH pattern of three different yogurt groups (control, commercial starter culture, and probiotics). Each group had three samples that were made using Dairyland 2% milk and corresponding cultures. The control group samples were not inoculated with any culture. The commercial starter culture group samples were inoculated with Yogourtmet Freeze-Dried Starter and the probiotics group samples were inoculated with probiotic capsule, Jamieson 10 Billion Probiotic. The samples were incubated for 7 hours and every 45 minutes the pH was measured using Hanna Professional Portable Yogurt pH Meter. Results: The statistical analysis of the pH measurement showed significant different between the control groups and other two groups. The control group samples pH decreased a bit, but it was not enough to turn the samples to a yogurt. The pH pattern of the commercial group samples showed rapid decrease in pH after 180 minutes and the average pH of the last reading was 4.10. The pH of the probiotics group samples decreased linearly, and the average pH of the last reading was 4.58. Conclusions: The commercial starter culture and the probiotics group samples initiated fermentation and enough acidification occurred to decrease the pH below 4.6. With 7 hours of incubation period, the probiotics group samples just met the pH that makes the yogurt safe to consume. Therefore, the use of the probiotics as a starter culture for producing yogurt can be suggested with adequate incubation period.  


10.5219/1377 ◽  
2020 ◽  
Vol 14 ◽  
pp. 300-306
Author(s):  
Peter Zajác ◽  
Lenka Kúšová ◽  
Lucia Benešová ◽  
Jozef Čapla ◽  
Jozef Čurlej ◽  
...  

In this work, we have compared and described the fermentation process of two commercial yogurt starter cultures during the white yogurt production. We used freeze-dried thermophilic starter culture YoFlex® YF - L812 and deep-frozen starter culture Delvo® Fresh YS – 241 for the production of white yogurts. We analysed titration acidity, active acidity, total viable counts, texture, and sensory parameters of white yogurts produced in laboratory conditions. This research was performed for dairy company Mliekareň Kopanice Selce, s.r.o., Slovakia. We did not found statistically significant differences (p >0.05) in titration acidity of both yogurts after 7 hours of fermentation. We did not found statistically significant differences (p >0.05) in the pH of both yogurts after 7 hours of fermentation. We found statistically significant differences (p <0.05) in all textural parameters (hardness, consistency, cohesion, and viscosity). The total viable count of microorganisms in yogurts after 24 hours of fermentation was 6.28 x 107 and 7.14 x 107 respectively.


Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1800
Author(s):  
Jolanta Król ◽  
Agnieszka Wawryniuk ◽  
Aneta Brodziak ◽  
Joanna Barłowska ◽  
Beata Kuczyńska

The study was conducted to determine the content and retention of selected fat-soluble vitamins and minerals in curd cheese–tvarog made by a traditional method, taking into account the effect of the quality of the raw milk and the type of starter cultures used. The raw milk used to make the tvarog was obtained in various conditions, i.e., with and without the use of pasture forage (in a traditional and an intensive system), in two production seasons (spring/summer and autumn/winter), from two breeds raised in Poland (the Black-and-White variety of Polish Holstein-Friesian and Simmental). Two variants of starter cultures were used to make tvarog: Freeze-dried DVS starters (Flora Danica) and pure cultures of mesophilic lactic acid bacteria. The acidity and content of protein, fat, selected fat-soluble vitamins (A, D3, and E), and selected macro-elements (Ca and Mg) were determined in samples of bulk milk and cheese. Retention rates of individual nutrients from the milk to the cheese were calculated. A higher content of fat-soluble vitamins was found in milk obtained from Simmental cows kept in a traditional system in the spring/summer season, as well as in the tvarog produced from it. Vitamin retention rates from the raw material to the tvarog were above 90%. The mineral composition of the cheese was not associated with the quality of the milk used. Very low retention rates from milk to cheese were obtained for Ca and Mg (below 20%). Higher retention rates were obtained in the spring/summer season when culture variant 1 was used. However, the starter culture was not found to significantly influence the concentration or retention of vitamins in the experimental cheese.


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