Characteristics Of Fermented Milk Research Articles

Stevia extract enhances the fermentation and functional properties of fermented milk in human colon epithelial cells

Yogurt or fermented milk (FM) stimulates the production of mucin in the colon epithelium, which helps protect against pathogens. Stevia is a natural sweetener containing functional compound, stevioside. In the present study, we aimed to investigate the effect of stevia leaves extract (ST) on FM and the health effect of ST-added FM on human colon cells. Thus, we investigated the impact of the extracts from stevia leaves on the fermentation and quality characteristics of FM. In addition, we assessed the impact of ST-supplemented FM on mucin production and its anti-inflammatory properties against Escherichia coli O157:H7 in human colon epithelial cells (HT-29/MTX). The FM was enriched with ST (0–0.5% w/v) and fermented using a mixture of lactic acid bacteria (LAB). A control FM supplemented with 0.5% sucrose. The results demonstrated that ST significantly increased the fermentation rate of FM by promoting the growth of LAB. ST supplementation resulted in an increase in the titratable acidity, water-holding capacity, total solid content, and viscosity of FM. Treatment of HT-29/MTX cells with STFM supernatants led to higher mucus production, as evidenced by an increase in the mRNA expression of MUC2, CDX2, and TFF3. Moreover, ST-added FM resulted in decreased mRNA levels of TNF-α, IL-1β, and IL-6, and adhesion of E. coli to HT-29/MTX cells. These results suggest that consuming ST-added FM may help reinforce the intestinal mucus layer and prevent inflammations related to pathogenic bacteria.

Donkey milk and fermented donkey milk: are there differences in the nutritional value and physicochemical characteristics?

This study aimed to evaluate the nutritional value and physicochemical characteristics of fresh donkey milk and fermented donkey milk. Furthermore, the impact of the refrigerated storage (4 °C, 21 days) on the characteristics of the fermented milk was evaluated. The fermented milk had higher acidity (lower pH values and higher titratable acidity) and presented lower lactose, mineral (calcium, phosphorous, magnesium, sodium, and zinc), and amino acid (mainly essential amino acids) contents than milk. Otherwise, it had a better fatty acid profile (lower saturated fatty acid content, and higher monounsaturated and polyunsaturated fatty acid contents). The fermented milk storage resulted in decreases in the lactose content, improvements in the amino acid profile, and maintenance of the mineral content. However, negative impacts were observed on the fatty acid profile. It can be concluded that both donkey milk and fermented milk donkey present important nutritional value, and the fermented milk could be refrigerated stored up to 21 days.

Goat Milk with Different Alpha-s1 Casein Genotype (CSN1S1) Fermented by Selected Lactobacillus paracasei as Potential Functional Food

The characteristics of fermented milk are affected by the type of milk used and the microorganisms involved in the fermentation process. Goat milk has been widely suggested as a possible alternative to cow milk in allergic subjects, because of the high genetic variability in alpha-s1 casein (CSN1S1) content, which is associated with different technological and nutritional properties of milk. The aim of the study was to evaluate the suitability of goat milk with low and high CSN1S1 to produce fermented milk. In addition, the performance as starter of selected Lactobacillus paracasei FS109 strain compared to no-selected L. paracasei strains was investigated. Initially, the selected L. paracasei FS109 strain was tested for adhesion ability to HT-29 and Caco-2 cells and immunomodulation effect. Then, the strain was used to produce fermented milk from goat milk with a low and high casein CSN1S1 genotype. The results indicated that greater acidifying activity was obtained for L. paracasei FS109 after 24 h of fermentation than the other two strains tested independently by the CSN1S1 genotype. L. paracasei FS109 grew well during fermentation, reaching a higher value (>8.5 log CFU/mL). Interestingly, the same strain maintained a high viable population (about 9 log CFU/mL) during the 30-day cold storage of the product. The present study shows for the first time the suitability of the goat milk with low CSN1S1 genotypes to produce fermented milk and highlight the importance of strain selection in determination of technological and beneficial traits. Combining goat milk with low CSN1S1 and selected strains could be a strategy of improving traditional and functional fermented milk market.

Growth of probiotic bacteria and characteristics of fermented milk containing fruit matrices

In this study, probiotic fermented milk beverages with black mulberry (MFM), red grape (GFM) and cornelian cherry (CFM) were produced. The viable cell counts of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus acidophilus and Bifidobacterium lactis were detected within the recommended biotherapeutic levels (>106 log cfu/mL) as a measure of the potential prebiotic effects of the components present in fruit‐based probiotic fermented milk. Variations in the pH, the syneresis and the colour values of the different milks were determined to be significantly different (P < 0.01). The value of the total antioxidant capacity in CFM samples was higher due to the high levels of ascorbic acid and total phenolic compounds. GFM samples had a more favourable taste than the other milks, despite similar overall sensory scores for all the fruit‐based fermented milks. We concluded the probiotic fermented milk drinks produced with black mulberry, red grape and cornelian cherry had high levels of probiotic bacteria and maintained their therapeutic activity during storage. Therefore, fermented milks incorporated with fruit matrices may be an alternative dairy product to deliver probiotic bacteria.

Acidification profile, probiotic in vitro gastrointestinal tolerance and viability in fermented milk with fruit flours

The effect of addition of apple, banana and grape flours (1%) on the characteristics of fermented milk by culture ABT-4 was evaluated. Supplementation with fruit flour affected only the acidification rate, and there was no effect on fermentation time. There was a decrease in the pH level and an increase in titratable acidity throughout storage. The level of probiotics was not affected by milk supplementation with fruit flours during 28 days of storage. Decreased probiotic survival during in vitro gastrointestinal simulation was observed in all the treatments. Nonetheless, the supplementation with fruit flours improved Lactobacillus acidophilus tolerance to simulated gastrointestinal conditions, specifically at days 14 and 28 of storage. On the other hand, only banana flour had a protective effect on Bifidobacterium animalis subsp. lactis after 28 days of storage. This is the first report that demonstrated a protective effect of fruit flours on the simulated gastrointestinal resistance of probiotics.

The Effect of Adding “Tape Singkong” (Fermented Cassava) Juice on the Characteristics of Fermented Milk

This study aimed to evaluate the effect of adding Tape Singkong juice on the characteristic of fermented milk. In the study 4000 ml of milk was used and divided into 20 cups (200 ml/cup). A completely randomized design that consist of five treatments with four replications was used to analyze the data. The treatment are the giving tape singkong juice as much as 0% (A), 22.5% (B), 5% (C), 7.5% (D) and 10% (E) into the milk that contained 2% of Lactobacillus acidophilus. The variable was observed the characteristic of fermented milk that consist of the moisture, fat, lactose and alcohol content, acidity and bacteria colony count. The result of this research indicated that the addition of tape singkong juice up to 7.5% was significantly decreased the content of moisture, fat and lactose and increased acidity, alcohol content and bacteria colony count.

English

The contribution of selected ropy and capsular Lactobacillus plantarum 162RM on texture of fermented milk as well as on the functionality of kareish cheese was established in this study. The cell suspension of this strain was used in combination with commercial starter cultures MY900 ( Lactobacillus delbrueckii ssp. Bulgaricus/I> and Streptococcus thermophilus ) and MM100 ( Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris and Lactococcus lactis ssp. diacetyllactis ) obtained from Rhodia Food to manufacture fermented milk and Kareish cheese respectively. The final pH of fermented milks manufactured with the combination of starter MY900 and different concentration of strain L. plantarum 162RM were not significantly different. Fermented milk hardness, consistency, and adhesiveness increased significantly when 8 % (V/V) of strain Lactobacillus plantarum 162RM was used. This strain produces exopolysaccharides (EPS), which by attaching to the casein matrix increases and improves the texture characteristics of fermented milk. The Experimental Kareish Cheese (EKC), made by pairing commercial starter MM100 with 8% (v/v) of L. plantarum 162RM were also compared to Control Kareich Cheese (CKC) in terms of their moisture content and textural properties. The EKC showed the greatest moisture retention and the use of ropy and capsular strain of L. plantarum 162RM affects significantly some textural properties of EKC cheese, relative to the control. The CKC samples were gummier and more chewy than the EKC fresh samples. It is therefore evident that, used in appropriate amount, this strain can increase moisture content in low fat Kareish cheese leading to improvement of textural properties. Key Words: Fermented milks, kareish cheese, ropy and capsular strain, moisture, textural properties. African Journal of Biotechnology Vol.3(10) 2004: 512-518