scholarly journals Evaluation of physical-chemical and microbiological characteristics of freeze-dried and reydrated yogurt

2020 ◽  
Vol 9 (6) ◽  
pp. e14962446
Author(s):  
Shana Kimi Farias Yamaguchi ◽  
Carolina Krebs de Souza ◽  
Sávio Leandro Bertoli ◽  
Lisiane Fernandes de Carvalho

This study aimed to evaluate the physical-chemical characteristics and the viability of lactic acid bacteria during the fermentation process of the yogurt and after the freeze-dried process, in addition to testing three thickener formulations for the rehydration of the yogurt powder. During the fermentation process, the production of lactic acid and the growth of lactic acid bacteria were accompanied.  Before and after freeze-dried process, yogurt was analyzed for pH, titratable acidity, carbohydrates, proteins, lipids and viable lactic acid bacteria. After lyophilization, three thickener formulations were tested to evaluate the rehydration of powdered yogurt. At the end of the fermentation process, it was verified that the lactic acid bacteria grew to reach 7.8.107 UFC.g-1 and the acidity obtained was 9.27 g.L-1.  The viable lactic acid bacteria count of freeze-dried and non-freeze-dried yogurt was 5.6.107 CFU.g-1 and 7.8.107 CFU.g-1, respectively. Non-freeze-dried and freeze-dried yogurts showed a content of 20.8% and 21.0% carbohydrates, 4.0% and 3.6% protein and 3.7% and 2.7% lipids, respectively. The combination of thickeners that provided viscosity similar to commercial yogurts was the guar gum, pectin and maltodextrin mix. Thus, it was possible to verify that the freeze-drying process maintains the physical-chemical characteristics and viability of lactic acid bacteria. In addition, the developed yogurt presented easy reconstitution at the time of consumption.

1999 ◽  
Vol 4 (2) ◽  
pp. 61
Author(s):  
N. Guizani ◽  
K. Al-Ramadani

Fifteen samples of Laban made at home in three Omani regions were subjected to physical-chemical and microbiological analysis. Laban had an average titratable acidity, pH, fat, protein and total solids of 1.12%, 3.98, 1.I2%, 2. 11% and 6.29%, respectively. The microbial flora of traditional Omani laban was found to be predominantly mesophilic lactococci. and homofemenentative lactobacili. The mean Lactococci and lactobacilli counts were 1.3 x 10 8 and 2.4 x 10 6/ml respectively. The main microbial types involved in the manufacture of Omani laban were Lactoeoccus lactis ssp lactis. Lacrococcus locus ssp locus biov. Diacetylactis, Lactococcus lactis ssp, Cremoris. and Lactobacillus plantarum. Leuconostoc species were present in low proportion compared to other lactic acid bacteria. All Laban samples contained high yeast numbers and were highly contaminated with coliforms, and fecal coliforms.


1996 ◽  
Vol 59 (9) ◽  
pp. 984-987 ◽  
Author(s):  
A. N. MUTUKUMIRA ◽  
S. B. FERESU ◽  
J. A. NARVHUS ◽  
R. K. ABRAHAMSEN

Chemical and microbiological analyses were carried out on 10 samples of raw milk collected over 6 months from the Nharira/Lancashire Milk Collection Center. The milk center is run by smallholder farmers. The purpose of the study was to evaluate the quality of the raw milk delivered to the milk collection center. The average chemical characteristics of the milk were (%): titratable acidity expressed as lactic acid, 0.21; total protein, 3.19; fat, 3.52; total solids, 11.76; and solids not fat, 8.25; the pH varied from 6.15 to 6.65. There were large variations in the microbiological composition of the raw milk with total aerobic counts ranging from 6.2 × 103 to 7.8 × 107 CFU/ml, coli forms from 3.2 × 102 to 2.3 × 105, and lactic acid bacteria from less than 1 × 103 to 2.9 × 106 CFU/ml. Yeasts and molds were less than 100 CFU/ml in 7 of the 10 samples analyzed.


2021 ◽  
Vol 247 ◽  
pp. 01001
Author(s):  
Irina Bazhenova ◽  
Elena Chernova ◽  
Tatiana Bazhenova

Global migration of populations leads to a widespread of national cuisines, which require adaptation to new consumers. In this regard, it is relevant to change traditional recipes and technologies. Here, we analyzed physical, chemical and organoleptic properties of the national Kyrgyz and Kazakh beverage Maksym. This beverage has a long history, unique properties, and at present is produced only by Shoro. Although being a Kyrgyz signature beverage, when not properly fomulated, it may cause acute intestinal infectious such as salmonellosis, dysentery, and typhoid fever. Our analysis showed that traditional beverage contains 0.9 g of protein, 4.38 g of carbohydrates, vitamins: B1 - 0.08mg%, B2 - 0.1mg%, PP - 0.4mg%, C - 0.59gr% with the useful-energy value of only 27 Kcal. This research analyzes variants of barms for the production of national Kyrgyz drink Maksym with different proportion of yeast and lactic-acid bacteria. Traditional Maksym composition and its production technology have been modified. For the produced drink, sediment content, titratable acidity, solids content, ethanol volume, nutritional and energy value, and organoleptic properties were tested.


2011 ◽  
Vol 194-196 ◽  
pp. 2156-2163 ◽  
Author(s):  
Shan Duan ◽  
Ying Xia Zhang ◽  
Ting Ting Lu ◽  
Dui Xi Cao ◽  
Jing Diao Chen

In this research, shrimp waste was fermented with 3 species of symbiotic lactic acid bacteria, namely Streptococcus thermophilus, Lactobacillus acidophilus and Lactobacillus bulgaricus. The ingredient changes occurring in the fermentation process were investigated. Results showed that the production of lactic acid in the fermentation process was remarkably improved, with the pH decreasing rapidly to 4.25 within 8 h, the lowest pH reaching 3.22, and the titratable acidity reaching 25.0 mmol/100ml. The improved acidic environment promoted the removal of calcium and protein, with 91.3% calcium, 97.7% protein and 32.3% carotenoid removed from shrimp waste after 168 h fermentation. The putrefaction was effectively prevented and the TVBN level was low throughout the whole process. Glucose was consumed rapidly in the earlier phase of the fermentation; about 69.4% glucose was consumed in the initial 24 h. The consumption of glucose was in well accordance with the growth of lactic acid bacteria, the removal of calcium and the increasing of titratable acidity. The amino nitrogen content kept increasing within 48 h, thereafter it came to decrease. 88.4% of peptides in the hydrolysate ranged between 1000 ~ 10000 Da, 10.2% smaller than 1000 Da, and 3.44% larger than 10000 Da.


Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2123
Author(s):  
Claudia Gallardo-Rivera ◽  
Juan G. Báez-González ◽  
Karla G. García-Alanís ◽  
Cynthia Torres-Alvarez ◽  
Karla Dares-Sánchez ◽  
...  

In this research, foaming technology was applied to obtain powdered yogurt from commercial yogurt at lower temperatures than the typical temperatures used during the dehydration process; the viability of lactic acid bacteria (LAB) was evaluated after the application of different drying techniques (conventional drying, freeze drying, and vacuum drying). Three different formulas (F1, F2, and F3) based on a foaming agent (albumen), stabilizers (guar gum), and prebiotics sources (inulin and agave syrup) were developed. Foam stability was evaluated at different pH values through optimum time of foam (OTF), medium drainage time (MDT), and drainage volume (DV). Foam expansion (FE) and foam density (FD) were measured. The OTF ranged from 6 to 10 min. The MDT ranged from 4.3 to 27.3 min, depending on pH, while the DV varied from 14.1 to 16.2 mL only in F1. No drainage was evidenced in F2 and F3, showing the best stability. The F2 and F3 produced the best FE and FD values. The dried yogurt with different techniques showed a survival rate (SR) of up to 85% Log-CFU/mL, even with the conventional drying method. Sensorial trials were carried out in reconstituted product, with the freeze-dried yogurt showing higher scores. The foam formulas developed demonstrate the efficacy of both the dehydration of yogurt and the preservation of LAB.


Food Research ◽  
2021 ◽  
Vol 5 (S2) ◽  
pp. 78-83
Author(s):  
D. Ishartani ◽  
D. Sistiani ◽  
A.M. Sari ◽  
A. Nursiwi ◽  
M.Z. Zaman

Lamtoro tempeh is a traditional Indonesian fermented food made from lamtoro (Leucaena leucocephala). In Pacitan, it is usually fermented using usar (a traditional tempeh inoculum made from senggani leaves). The fermentation process takes 42 hrs and during this period, there are changes in the chemical and microbiological characteristics of the lamtoro seeds. To study these changes, samples were collected and tested for chemical characteristics (water content, ash content, dissolved protein, pH, and total acid titration) and microbiological characteristics (the number of fungi, yeast, and lactic acid bacteria) every 6 hrs during the 42 hrs fermentation. During fermentation, the water content increased significantly in the initial 6 hrs of fermentation and then tended to stabilize until the 42-hour. The ash content increased, while the dissolved protein content increased from the 0-hour to the 36-hour of fermentation but dropped at the 42-hour. The pH level of the lamtoro tempeh decreased from 0-hour until 30-hour and then increased until the end of the fermentation period. However, the level of total acid titration increased during the lamtoro tempeh fermentation. The growth of fungi, yeast and lactic acid bacteria initially declined but then gradually increased until the end of fermentation (42-hour). The fermentation time was found to affect both the number of microbes and the chemical characteristics of the lamtoro tempeh from the Pacitan area.


Author(s):  
N. E. Posokina ◽  
E. S. Shishlova ◽  
A. I. Zakharova

Fermented cabbage is traditionally produced naturally, where under the action of lactic acid bacteria contained in raw materials, carbohydrates are converted into lactic acid. However, the direct fermentation process does not always lead to an optimal quality product. That is why the use of lactic acid microorganisms is a good alternative to the direct fermentation of cabbage, as with the help of starter cultures the process can be controlled. In this connection, the use of strains of lactic acid microorganisms allows to achieve rapid production of lactic and acetic acids and leads to a rapid decrease in pH, which in turn leads to the suppression of pathogenic microflora, and therefore to the creation of favorable conditions for the fermentation process. The aim of this study was to study the effect of consortia of lactic acid microorganisms on the dynamics of active and titratable acidity in the main stage of fermentation of white cabbage of the variety "Parus". For the study, the prepared modified model medium (MMC) from cabbage was used. In this work, we used lactic acid bacteria Leuconostoc mesenteroides and its consortia: L. mesenteroides + L. casei, L. mesenteroides + L. plantarum, L. mesenteroides + L. brevis, L. mesenteroides + L. casei + L. plantarum, L. mesenteroides + L. plantarum + L. brevis, L. mesenteroides + L. brevis + L. casei. Mathematical processing was carried out according to the obtained experimental data. Analysis of experimental data showed that at the main stage of fermentation the relationship of lactic acid microorganisms in the studied consortia was expressed by synergistic and antagonistic properties. In this case, the best results on the dynamics of growth of active and titratable acidity were obtained in consortiums L. mesenteroides + L. plantarum, L. mesenteroides + L. casei + L. plantarum, L. mesenteroides + L. plantarum + L. brevis.


Biotecnia ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 93-101
Author(s):  
Elia Morales-Nolasco ◽  
Lourdes Adriano-Anaya ◽  
Didiana Gálvez-López ◽  
Raymundo Rosas-Quijano ◽  
Alfredo Vázquez- Ovando

El objetivo del presente trabajo fue aislar bacterias ácido lácticas de leche y queso crema del estado de Chiapas, México y evaluar su efecto como cultivo iniciador en las características fisicoquímicas (color, firmeza, consistencia, humedad, acidez titulable, proteína, grasa y cenizas), sensoriales (sabor, aroma, textura, cremosidad y acidez) y microbiológicas (coliformes totales, mohos y levaduras) del mismo queso elaborado a partir de leche pasteurizada. Mediante resiembra consecutiva en placas con agar MRS, se aislaron 101 cepas de diferentes morfologías a partir de muestras de leche y queso crema elaborado con leche no pasteurizada, de las cuales 26 fueron presuntivamente ácido lácticas. Por su capacidad acidificante (descenso del pH) se seleccionaron siete cepas, con las cuales se formularon tres tratamientos (combinaciones de tres cepas, denominados T2-T4). El tratamiento que, después del queso control (T1) sensorialmente fue el más aceptado por los jueces, se reformuló en tres nuevas combinaciones de dos cepas (T5-T7). De estos tratamientos, el T5 (cepas E16 y E23) fue similar en color, aroma, sabor, textura y cremosidad al control (queso elaborado con leche sin pasteurizar). A pesar de que fueron diferentes en cuanto a la acidez, los jueces no lograron diferenciar (prueba cuantitativa) el queso T5 del control.ABSTRACTThe aim of this work was to isolate lactic acid bacteria from milk and ‘queso crema’ cheese and evaluate their effect as starter on physicochemical (color, firmness, consistency, moisture, titratable acidity, protein, fat, and ash), sensory (flavor, aroma, texture, creaminess and sourness), and microbiological (total coliforms, molds and yeasts) characteristics of the same cheese made using pasteurized milk. By consecutive plating on MRS agar, 101 strains of different morphologies were isolated from samples of milk and cheese made with unpasteurized milk, of which 26 were presumptively lactic acid. Due to its acidifying capacity (measured as a decreased in pH), seven strains were selected, with which three treatments were formulated (combinations of three strains, called T2-T4). The treatment that, after the control cheese (T1) was the most accepted by the judge’s panel, was reformulated in three new combinations of two strains each (T5-T7). Of these treatments, T5 (containing strains E16 and E23) was similar in color, aroma, flavor, texture and creaminess to the control (cheese made with unpasteurized milk). Although the T5 cheese was different to control in acidity, the judges could not differentiate (quantitative test) between both samples.


Author(s):  
Oumarou Djobo ◽  
Abdou Hamidou Soule ◽  
Haziz Sina ◽  
Souriatou B. Tagba ◽  
Farid Baba-Moussa ◽  
...  

Aims: The production of “wagashi”, induce the production of whey which is often directly drop in the environment. The aim of this study was to evaluate the microbiological and physicochemical qualities of wagashi’s whey samples collected in Abomey-Calavi (Benin). Methodology: Whey samples were collected from Abomey-Calavi (Parana and Akassato) in Southern Benin. The physicochemical analyses targeted the pH, titratable acidity, dry matter contents, protein and lactose. The microbiological analyzes carried out consisted in enumeration of total mesophilic flora (TMF), fecal coliforms, lactic acid bacteria, staphylococci, yeasts and molds, Pseudomonas, Escherichia coli and salmonella by cultures on specific synthetic nutrient media. Results: This study revealed characteristics such as dry matter (5.30-5.66 g / l), pH (3.91-5.21), titratable acidity, protein (5.94-0.128 g / l), lactose; and microbial quality of the whey. Parana’s whey was more acidic (pH = 3.91 ± 0.014) than Akassato’s whey analyzed with higher titratable acidity (pH = 0.92 ± 0.01). The presence of total mesophilic aerobic flora, Escherichia coli, staphylococci, lactic acid bacteria, yeasts and molds reveals fecal, human and environmental contamination during cheese production or during whey storage. Thus, Parana's whey was more contaminated with TMF (3.45.108 CFU/ml), lactic acid bacteria (4.82.108 CFU/ml) and fecal coliforms (> 3.108 CFU/ml) while Akassato's whey was more contaminated by staphylococci (4.70.108 CFU/ml) and Escherichia coli (> 3.108 CFU/ml). Salmonella was not identified. Conclusion: It thus important raising the awareness of cow's milk processors and / or whey producers in Benin. We therefore project to use this whey as a substrate for bioproduction.


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