III. LIPOLYTIC ACTIVITY1

1971 ◽  
Vol 34 (2) ◽  
pp. 69-73 ◽  
Author(s):  
Antonieta Gaddi Angeles ◽  
E. H. Marth

The following lactic acid bacteria, when tested with the agar-well method, were able to hydrolyze tributyrin and triolein, but not soybean oil: Streptococcus lactis, Streptococcus cremoris, Streptococcus diacetilactis, Streptococcus thermophilus, Leuconostoc mesenteroides, Pediococcus cerevisiae, Lactobacillus delbrueckii, Lactobacillus casei, Lactobacillus pentosus, and Lactobacillus brevis. Tributyrin only was hydrolyzed by Lactobacillus helveticus. Some free fatty acids were liberated by L. casei, L. delbrueckii, and S. thermophilus in soymilk (1.9% soybean lipids) and in MRS broth fortified with 2.0% soybean oil during a 14-day period of incubation. Although L. casei and L. delbrueckii were more active in soymilk than was S. thermophilus, they released about 10% of the amount of free fatty acids liberated by Candida lipolytica during a similar incubation period.

1971 ◽  
Vol 34 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Antonieta Gaddi Angeles ◽  
E. H. Marth

Soymilk with a protein content similar to that of cow's milk was prepared from soybeans (variety Chippewa 64). Soybeans were washed, soaked until 1 ml of water per gram of beans was absorbed, comminuted with water equivalent to 7.6 times their dry weight, and the mixture filtered through cheese cloth to obtain an aqueous extract free of large particles. Growth rates of 13 species of lactic-acid bacteria in sterile soymilk were generally greater than or comparable to those in cow's milk or Elliker's broth. Acid production in soymilk was not always directly related to growth rates of the organisms. Substantial formation of acid was limited to those bacteria able to utilize the sugars in soymilk, e.g., Streptococcus thermophilus, Lactobacillus delbrueckii, Lactobacillus pentosus, and Leuconostoc mesenteroides. Sources of readily available nitrogen (e.g., protein digests), when added to soymilk, enhanced acid production by S. thermophilus, the Leuconostoc species, and L. pentosus; appeared inhibitory to L. delbrueckii; and had no apparent effect on the other test cultures. Addition of whey powder, glucose, or lactose to soymilk enhanced acid production by Streptococcus lactis, Streptococcus cremoris, Streptococcus diacetilactis, Lactobacillus casei, and Lactobacillus helveticus; whereas addition of sucrose was without benefit. The presence of 0.23–0.25% titratable acid, corresponding to a pH of 5.7, caused coagulation of the sterilized soymilk.


2011 ◽  
Vol 2 (4) ◽  
pp. 335-339 ◽  
Author(s):  
N. Karapetkov ◽  
R. Georgieva ◽  
N. Rumyan ◽  
E. Karaivanova

Five lactic acid bacteria (LAB) strains belonging to species Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis and Streptococcus thermophilus were tested for their susceptibility to 27 antibiotics. The minimum inhibitory concentrations of each antimicrobial were determined using a microdilution test. Among the strains a high susceptibility was detected for most of the cell-wall synthesis inhibitors (penicillins, cefoxitin and vancomycin) and resistance toward inhibitors of DNA synthesis (trimethoprim/sulfonamides and fluoroquinolones). Generally, the Lactobacillus strains were inhibited by antibiotics such as chloramphenicol, erythromycin and tetracycline at breakpoint levels lower or equal to the levels defined by the European Food Safety Authority. Despite the very similar profile of S. thermophilus LC201 to lactobacilli, the detection of resistance toward erythromycin necessitates the performance of additional tests in order to prove the absence of transferable resistance genes.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1826
Author(s):  
Miriam Zago ◽  
Lia Rossetti ◽  
Tommaso Bardelli ◽  
Domenico Carminati ◽  
Nelson Nazzicari ◽  
...  

The microbiota of Protected Designation of Origin (PDO) cheeses plays an essential role in defining their quality and typicity and could be applied to protect these products from counterfeiting. To study the possible role of cheese microbiota in distinguishing Grana Padano (GP) cheese from generical hard cheeses (HC), the microbial structure of 119 GP cheese samples was studied by DNA metabarcoding and DNA metafingerprinting and compared with 49 samples of generical hard cheeses taken from retail. DNA metabarcoding highlighted the presence, as dominant taxa, of Lacticaseibacillus rhamnosus, Lactobacillus helveticus, Streptococcus thermophilus, Limosilactobacillus fermentum, Lactobacillus delbrueckii, Lactobacillus spp., and Lactococcus spp. in both GP cheese and HC. Differential multivariate statistical analysis of metataxonomic and metafingerprinting data highlighted significant differences in the Shannon index, bacterial composition, and species abundance within both dominant and subdominant taxa between the two cheese groups. A supervised Neural Network (NN) classification tool, trained by metagenotypic data, was implemented, allowing to correctly classify GP cheese and HC samples. Further implementation and validation to increase the robustness and improve the predictive capacity of the NN classifier will be needed. Nonetheless, the proposed tool opens interesting perspectives in helping protection and valorization of GP and other PDO cheeses.


1972 ◽  
Vol 35 (8) ◽  
pp. 489-495 ◽  
Author(s):  
H. s. Park ◽  
E. H. Marth

Cultured skimmilks containing Salmonella typhimurium were prepared at 21, 30, or 42 C using different species of lactic acid bacteria (0.25, 1.0, and 5% inoculum) either singly or in combinations. Several commercial cultures also were used. Cultured skimmilks were stored at 11 C and tested at 3-day intervals for numbers of viable salmonellae and lactic acid bacteria and for pH. Survival of S. typhimurium varied from 6 to 9 days and from 3 to 6 days in milks cultured with 0.25% Streptococcus lactis at 21 and 30 C, respectively. Increasing the inoculum to 1% with incubation at 30 C yielded a product no more detrimental to S. typhimurium than when the lower inoculum was used at 30 C. Survival of S. typhimurium always exceeded 9 days when S. cremoris was used to make cultured skimmilks. Products made with commercial mixed cultures composed of S. lactis and S. cremoris allowed S. typhimurium to survive for periods intermediate between the extremes observed when pure cultures were used. Skimmilks cultured with Streptococcus diacetilactis and Leuconostoc citrovorum, even when skimmilks cultured with the latter organism were acidified with citric acid and incubated further, were essentially without effect on survival of S. typhimurium during refrigerated storage. Use of Streptococcus thermophilus (1% culture, 42 C incubation) yielded cultured skimmilks that were most detrimental to survival of salmonellae, whereas skimmilks fermented with Lactobacillus bulgaricus permitted survival of low numbers of salmonellae beyond 9 days. Milks cultured at 42 C with a 5% inoculum of S. thermophilus mixed with L. bulgaricus or Lactobacillus helveticus were free of viable salmonellae before the incubation was complete. Salmonellae grown in skimmilk at 21 C without a lactic culture were more resistant to inactivation during refrigerated storage than was S. typhimurium grown at 30 or 42 C.


1998 ◽  
Vol 75 (5) ◽  
pp. 563-568 ◽  
Author(s):  
I. H. Rukunudin ◽  
P. J. White ◽  
C. J. Bern ◽  
T. B. Bailey

Author(s):  
MARINALDA DA SILVA SOARES ◽  
ANA PAULA BADAN RIBEIRO ◽  
LIRENY APARECIDA GUARALDO GONÇALVES ◽  
GABRIELA B. FERNADES ◽  
HELENA MARIA ANDRÉ BOLINI

Este trabalho teve como objetivo verificar se existe diferença sensorial significativa ao nível de consumidor quanto à aceitação dos atributos aroma e sabor entre o óleo de soja degomado por ultrafiltração e desodorizado e óleo de soja refinado comercial, obtido tradicionalmente. Amostras com 20 litros de miscela do óleo de soja bruto foram ultrafiltradas em membranas cerâmicas de 19 e 37 canais (comprimento de 1 m e 0,01 µm de diâmetro de poro) e desodorizadas sob nitrogênio a 230 ºC, após separação do solvente. Os óleos desodorizados obtidos mostraram coloração mais intensa com preservação de carotenóides e, em média, 0,25% de ácidos graxos livres, enquadrando-se na faixa estabelecida pela legislação brasileira (valores inferiores a 0,3% em ácido oléico). O índice de peróxido também atendeu às exigências para óleo desodorizado para fins comestíveis. As amostras obtidas não diferiram significativamente (p ≤ 0,05) entre si e nem do óleo de soja refinado disponível comercialmente. SENSORY ACCEPTANCE OF SOYBEAN OIL DEODORIZED AND DEGUMMED BY ULTRAFILTRATION Abstract This work had as objective to verify if it exists significant sensorial difference at consumers level of soybean oil degummed by ultrafiltration and comercial refined, traditionally obtained soybean oil in relation to aroma and flavor attributes. Samples with 20 L of miscella of crude soybean oil were ultrafiltrated in ceramic membranes of 19 and 37 channels (1 m lenght and 0.01 mm of pore diameter) and deodorized with nitrogen at 230ºC after solvent separation. The deodorized oils obtained showed more intense pigmentation with preservation of carotenoids and, in average, 0.25% of free fatty acids, within the range established by the Brazilian legislation (values inferior to 0.3% in oleic acid). The peroxide indice also attended the exigences for edible deodorized oils. The samples obtained didn’t differ significantly (p ≤ 0.05) among each other neither with the refined commercially available soybean oil.


2014 ◽  
Vol 20 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Maja Bulatovic ◽  
Marica Rakin ◽  
Ljiljana Mojovic ◽  
Svetlana Nikolic ◽  
Maja Vukasinovic-Sekulic ◽  
...  

The aim of this study was improvement of the performances for the production of whey-based beverages with highly productive strains of Lactobacillus. Individual or mixed culture containing Lactobacillus helveticus ATCC 15009, Lactobacillus delbrueckii ssp. lactis NRRL B-4525 and Streptococcus thermophilus S3 were studied. The scientific hypothesis was that production performances, especially aroma and viable cell count, are positively affected by the strains combination and temperature. Based on the results, beverages obtained by mixed cultures Lb. helveticus ATCC 15009 - S. thermophilus S3 and Lb. delbrueckii ssp. lactis - S. thermophilus S3 had higher aroma values than beverages obtained by individual strains. The symbiosis of tested strains has positive impact on the aroma of produced beverage. In addition, the temperature has significant influence on cell viability during the storage and fermentation dynamic. The beverages produced by mixed cultures Lb. helveticus ATCC 15009 - S. thermophilus S3 and Lb. delbrueckii ssp. lactis - S. thermophilus S3 at 42 oC achieved higher storage stability (19 to 22 days) than beverages produced at 37?C and 45?C (13 to 19 days). Subsequently, at 42 ?C fermentation time for both mixed cultures was 1.5 h shorter, compared to the time achieved at 37?C.


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