scholarly journals Impact of Milk Fortification on the Microbiological and Physicochemical Properties of Set-Type Skimmed Yoghurt Using Three Commercial Soluble Prebiotics

Foods ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 181 ◽  
Author(s):  
Rui Li ◽  
Qi Ding ◽  
Xin-Huai Zhao
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Physicochemical Properties ◽  
Acid Content ◽  
Titratable Acidity ◽  
Lactobacillus Delbrueckii ◽  
Chemical Compositions ◽  
Acid Fermentation ◽  
Ph Values ◽  
The Impact

The impact of milk fortification on the microbiological and physicochemical properties of a set-type skimmed yoghurt using three commercial soluble prebiotics (inulin, iso-malto-oligosaccharides, and xylo-oligosaccharides) at either 3 or 5 g/kg was assessed. The three prebiotics had an insignificant impact on yoghurt fermentation because all yoghurt samples had similar titratable acidity and similar pH values after their lactic acid fermentation. Regarding the control yoghurt samples without prebiotics usage, the prebiotics-fortified yoghurt samples showed no difference in their main chemical compositions, hardness, syneresis extent, and apparent viscosity (p > 0.05), but had a slightly higher lactic acid content and a viable quantity of starter strains. All yoghurt samples had the same acetic acid content, while propionic and butyric acids were not produced. Yoghurt storage at 4 °C for 21 day gave these yoghurt samples decreased pH values and a viable quantity of starter strains (especially Lactobacillus delbrueckii subsp. bulgaricus) and unchanged acetic acid; however, it increased lactic acid contents. Overall, prebiotics fortification up to 5 g/kg had a completely insignificant impact on the fermentation and quality attributes of yoghurt samples but could possibly improve the health of consumers due to higher dietary fibers and starter strain populations.

scholarly journals Considerations on the Dynamics of the pH Values and Lactic Acid Content during Lactic Acid Fermentation of Carrot Juices with Different Pure Cultures

1970 ◽  
Vol 66 (2) ◽  
Author(s):  
Gabriel GORGHIU ◽  
Lavinia BURULEANU ◽  
Carmen Leane NICOLESCU ◽  
Daniela AVRAM
Keyword(s):  
Lactic Acid ◽  
Acid Content ◽  
Lactic Acid Fermentation ◽  
Regression Equations ◽  
Acid Fermentation ◽  
Software Application ◽  
Related Data ◽  
Ph Values ◽  
Lactic Acid Content ◽  
Pure Cultures

Suitability of the carrots for obtaining lactic acid fermented juices using different lactic acid bacteria and Bifidobacterium sp. that are not constitutive from the epiphytic microbiota of vegetables was tested. One the one hand, the aim of this work was to obtain related data to the dynamics of the titrable acidity and the pH during the course of the controlled fermentation, due of the importance of these parameters on the shelf life of the final products. Optimum type of culture and optimum amount of inoculum was determined. On the other hand, the work proposes also model predictions for expressing the pH values and the lactic acid content dynamics, during lactic acid fermentation of carrot juices with different pure cultures. Using the CurveExpert 1.3 software application, specific regression equations were determined.

scholarly journals Qualitative Studies on Chhana Prepared from Cow and Buffalo Milk

2018 ◽  
Vol 6 (7) ◽  
pp. 936
Author(s):  
Sarfraz Ahmed ◽  
Dilpat Rai Menghwar ◽  
Ubaid Qureshi ◽  
Tanveer Ahmed ◽  
Salahuddin Jakhrani
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Citric Acid ◽  
Significant Influence ◽  
Concentration Level ◽  
Titratable Acidity ◽  
Buffalo Milk ◽  
Qualitative Studies ◽  
Cow Milk ◽  
Ph Values

Qualitative studies on chhana were carried out at Sindh Agriculture University Tandojam during the year 2011-12. Two milk sources (i.e. cow milk and buffalo milk) and three coagulants (i.e. acetic acid, citric acid and lactic acid) were used during the study period. Physical characteristics such as titratable acidity and pH values. Preliminary, the chhana was prepared from each of cow and buffalo milk coagulated with acetic acid, citric acid, and/or lactic acid each at 0.5, 1, 2 and 4% concentration level. Among each coagulant, concentration level showed significant influence on the acceptability score of chhana. Product made with 0.5% concentration level perceived the better acceptability (score). A remarkable influence of milk source was observed in pH values of chhana prepared from cow milk and buffalo milk either with acetic acid (5.65±0.01 and 5.45±0.01, respectively) or with citric acid (5.52±0.02 and 5.45±0.01, respectively). In this study, buffalo milk chhana was found better in all aspects compared to that of cow milk.

scholarly journals Bacterial and Fungal Microbiota of Guinea Grass Silage Shows Various Levels of Acetic Acid Fermentation

Fermentation ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 10
Author(s):  
Jianjian Hou ◽  
Naoki Nishino
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Acid Content ◽  
Storage Period ◽  
Acid Fermentation ◽  
Acetic Acid Fermentation ◽  
Grass Silage ◽  
Guinea Grass ◽  
Fungal Microbiota ◽  
And Storage

This study aimed to gain insights into the bacterial and fungal microbiota associated with the acetic acid fermentation of tropical grass silage. Direct-cut (DC, 170 g dry matter [DM]/kg) and wilted (WT, 323 g DM/kg) guinea grass were stored in a laboratory silo at moderate (25 °C) and high (40 °C) temperatures. Bacterial and fungal microbiota were assessed at 3 days, 1 month, and 2 months after ensiling. Lactic acid was the primary fermentation product during the initial ensiling period, and a high Lactococcus abundance (19.7–39.7%) was found in DC silage. After two months, the lactic acid content was reduced to a negligible level, and large amounts of acetic acid, butyric acid, and ethanol were found in the DC silage stored at 25 °C. The lactic acid reduction and acetic acid increase were suppressed in the DC silage stored at 40 °C. Increased abundances of Lactobacillus, Clostridium, and Wallemia, as well as decreased abundances of Saitozyma, Papiliotrema, and Sporobolomyces were observed in DC silages from day three to the end of the 2 month period. Wilting suppressed acid production, and lactic and acetic acids were found at similar levels in WT silages, regardless of the temperature and storage period. The abundance of Lactobacillus (1.72–8.64%) was lower in WT than in DC silages. The unclassified Enterobacteriaceae were the most prevalent bacteria in DC (38.1–64.9%) and WT (50.9–76.3%) silages, and their abundance was negatively related to the acetic acid content. Network analysis indicated that Lactobacillus was involved in enhanced acetic acid fermentation in guinea grass silage.

Probiotic Greek yogurt: effect of the addition of prebiotic fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance

2021 ◽  
Vol 88 (1) ◽  
pp. 98-104
Author(s):  
Sofia Sestito Dias ◽  
Damarys de Souza Vergílio ◽  
Arthur Marroni Pereira ◽  
Suellen Jensen Klososki ◽  
Vanessa Aparecida Marcolino ◽  
...  
Keyword(s):  
Negative Impact ◽  
Storage Period ◽  
Titratable Acidity ◽  
Physicochemical Characteristics ◽  
Modified Starch ◽  
Sensory Acceptance ◽  
Ph Values ◽  
Fat Substitutes ◽  
Gastrointestinal Conditions ◽  
The Impact

AbstractIn this research communication we evaluate the impact of the addition of prebiotic components (inulin, polydextrose, and modified starch, 40 g/l) as fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance of probiotic (Lacticaseibacillus casei 01, 108 CFU/ml) Greek yogurts during storage (7 °C, 28 d). All formulations had probiotic counts higher than 107 CFU/ml during storage and simulated gastrointestinal conditions (SGIC). The prebiotic components increased the probiotic survival to the enteric phase of the SGIC, with inulin producing the most pronounced effect. Inulin addition resulted in products with lower pH values and consistency and higher titratable acidity during storage, with negative impact on the sensory acceptance (flavor, texture, and overall impression) at the end of the storage period. Modified starch addition impacted negatively on the acceptance of the products (appearance, flavor, texture, and overall impression). Polydextrose addition resulted in products with lower consistency, but similar sensory acceptance to the full-fat yogurt. It can be concluded that it is possible to prepare potentially synbiotic Greek yogurts by desorption technique using L. casei as probiotic culture and inulin, polydextrose or modified starch as prebiotic components, with the utilization of polydextrose being advisable.

Bacterial Spoilage of Citrus Products at pH Lower than 3.51

1976 ◽  
Vol 39 (12) ◽  
pp. 819-822 ◽  
Author(s):  
B. J. JUVEN
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Thermal Resistance ◽  
Tartaric Acid ◽  
Lactobacillus Brevis ◽  
Acid Inhibition ◽  
Temperature Range ◽  
Ph Values ◽  
Sugar Syrup ◽  
Z Value

A strain of Lactobacillus brevis, L-3, was isolated from a blown can of grapefruit segments in sugar syrup; it caused spoilage of citrus products having pH values lower than 3.5. When inoculated into orange (pH 3.38) and grapefruit (pH 2.99) juices, after 5 h at 30 C L-3 produced 15 and 22 μg diacetyl/ml, respectively, and off-flavor was detectable. L-3 grew in APT broth acidified to pH 3.0 with citric, hydrochloric, phosphoric, or tartaric acid. However, its growth was inhibited at pH 3.6 if the acidulant was lactic acid, while with acetic acid inhibition occurred at a pH between 3.7 and 4.0. The thermal resistance of L-3 in orange serum (pH 3.4) was studied in the temperature range of 52 to 60 C: a z value of 8.3 was obtained. A simple and reliable capillary technique for studying the thermal resistance of gas-producing organisms in liquid foods and media is presented.

Effect of pH, Acidulant, Time, and Temperature on the Growth and Survival of Listeria monocytogenes

1989 ◽  
Vol 52 (8) ◽  
pp. 571-573 ◽  
Author(s):  
KENT M. SORRELLS ◽  
DAVIN C. ENIGL ◽  
JOHN R. HATFIELD
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Hydrochloric Acid ◽  
Malic Acid ◽  
Incubation Temperature ◽  
Growth And Survival ◽  
Ph Values

The effect of different acids, pH, incubation time, and incubation temperature on the growth and survival of four strains of Listeria monocytogenes in tryptic soy broth was compared. Hydrochloric acid (HCl), acetic acid (AA), lactic acid (LA), malic acid (MA), and citric acid (CA) were used to acidify tryptic soy broth to pH values 4.4, 4.6, 4.8, 5.0, and 5.2 pH. Incubation times were 1, 3, 7, 14, and 28 d at 10, 25, and 35°C. The inhibition of L. monocytogenes in the presence of high acidity appears to be a function of acid and incubation temperature. Based on equal pH values, the antimicrobial activity is AA > LA > CA ≥ MA > HCl at all incubation times and temperatures. When based on equal molar concentration, the activity appeared to be CA ≥ MA > LA ≥ AA > HCl at 35 and 25°C, and MA > CA > AA ≥ LA > HCl at 10°C. Greatest antimicrobial activity occurred at 35°C. Greatest survival occurred at 10°C and greatest growth occurred at 25°C. Final pH of the medium was as low as 3.8 in HCl at 28 d. All strains grew well at pH values lower than the minimum previously reported (5.5–5.6).

GROWTH OF STAPHYLOCOCCUS AUREUS IN ACIDIFIED PASTEURIZED MILK1

1970 ◽  
Vol 33 (11) ◽  
pp. 516-520 ◽  
Author(s):  
T. E. Minor ◽  
E. H. Marth
Keyword(s):  
Staphylococcus Aureus ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Hydrochloric Acid ◽  
Ph Value ◽  
The Other ◽  
Antagonistic Effects ◽  
Pasteurized Milk ◽  
Ph Values ◽  
Effect On Growth

The effect of gradually reducing the pH of pasteurized milk with acetic, citric, hydrochloric, lactic, and phosphoric acids over periods of 4, 8, and 12 hr on growth of Staphylococcus aureus 100 in this substrate was determined. In addition, 1: 1 mixtures of lactic acid and each of the other acids, and of acetic and citric acids were evaluated for their effect on growth of this organism. To achieve a 90% reduction in growth over a 12 hr period, a final pH value of 5.2 was required for acetic, 4.9 for lactic, 4.7 for phosphoric and citric, and 4.6 for hydrochloric acid. A 99% reduction during a 12 hr period was obtained with a final pH value of 5.0 for acetic, 4.6 for lactic, 4.5 for citric, 4.1 for phosphoric, and 4.0 for hydrochloric acid. A pH value of 3.3 was required for a 99.9% reduction with hydrochloric acid, whereas the same effect was produced at a pH value of 4.9 with acetic acid. Correspondingly lower pH values were required to inhibit growth within 8 and 4 hr periods. Mixtures of acids adjusted to pH values at the borderline for growth (12 hr period) exhibited neither synergistic nor antagonistic effects between two acids.

scholarly journals Recycling Of Peneapple Waste Using Lactobacillus Delbroeckii to Lactic Acid

REAKTOR ◽  
2017 ◽  
Vol 5 (2) ◽  
pp. 79
Author(s):  
Abdullah Abdullah ◽  
H. B. Mat
Keyword(s):  
Lactic Acid ◽  
Yeast Extract ◽  
Lactic Acid Production ◽  
Lactobacillus Delbrueckii ◽  
Raw Material ◽  
Acid Fermentation ◽  
Fermentation Time ◽  
Pineapple Waste ◽  
Fermentation Liquid ◽  
Initial Ph

The liquid pineapple waste contain mainly sucrose, glucose, fructose, and other nutrients. It therefore can potentiall be used as carbon source for organic acid fermentation. Recently, lactic acid has been considered to be an important raw material for production of biodegradadable lactace polymer. The experiments weree carried out in shake flash fermentation using lactobacillus delbroeckii. Effect of some parameters such as temperature, initial Ph, initial substrate concentration, yeast extract concentration and fermentation time to the yield have been studied. The highest yield was 85.65% achieved at 40 0C, PH 6.00, 52.2 g/l sugar concentration with 5 g/l yeast extract. There was no significant increasing in lactic acid production was observed if supplementation of yeast extract above 10%.Keyword : lactic acid fermentation, liquid pineapple waste, lactobacillus delbrueckii

scholarly journals Approaches to improve the growth of the starter lactic acid bacterium OM13 during the early stages of green Spanish-style table olive production

2018 ◽  
Vol 69 (3) ◽  
pp. 265
Author(s):  
A. Alfonzo ◽  
A. Martorana ◽  
L. Settanni ◽  
M. Matraxia ◽  
O. Corona ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Starter Culture ◽  
Table Olives ◽  
Acid Fermentation ◽  
Lactobacillus Pentosus ◽  
Ph Values ◽  
Organoleptic Characteristics ◽  
Fermented Product ◽  
And Control

The present research aimed at determining the optimal conditions for the lactic acid fermentation of green Spanish-style table olives. The work is a follow-up, and focuses on the performance of the commercial starter strain Lactobacillus pentosus OM13 by applying an acclimatization step and the addition of nutrients, and concentrations of lactic acid that were previously investigated. The acclimatization of the cells warranted the dominance of the starter culture even at an inoculation level of 2 Log cycles lower than that commonly used in standard fermentation. A significant effect was found in terms of acidification kinetics within the first week of fermentation, with the highest decrease in pH, at ~2.5 units, which occurred in the trial and after inoculation with 106 CFU/mL of starter after acclimatation (EO3) that showed values similar to control C obtained with Lactobacillus pentosus OM13 at a concentration of 107 CFU/mL. After day 3, further decreases in pH of up to 4.30 were observed until day 30, and then these values remained almost constant until the end of process (day 190) when lower pH values were reached for trial EO3 and control C. The results of microbiological dynamics, the changes in VOCs and finally the effect of the processes on the sensory analysis of the fermented product were investigated by multivariate analysis. The acclimatization process and the initial inoculation level influenced the bacterial microflora, aromatic compounds and organoleptic characteristics of the final product. Finally, the trials C, EO2 and EO3 showed higher values (60-80%) of preferences and satisfaction compared to other experimental productions.

scholarly journals Production of a cereal based product (Ogi): Influence of co-fermentation with powdered garlic and ginger on the microbiome

Agrosearch ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 81-93
Author(s):  
A.F. Olaniran ◽  
S.H. Abiose ◽  
H.A. Adeniran ◽  
S.O. Gbadamosi ◽  
Y.M. Iranloye
Keyword(s):  
Lactic Acid ◽  
Candida Utilis ◽  
Titratable Acidity ◽  
Candida Krusei ◽  
Quality Protein Maize ◽  
Microbial Count ◽  
Food Effects ◽  
Weaning Food ◽  
Acid Fermentation ◽  
Total Titratable Acidity

Many African foods undergo lactic acid fermentation; alterations of these germane microorganisms during fermentation of ogi can affect its acceptability as a weaning food. Effects of garlic and ginger on microorganisms’ load during the production of fermented cereal (ogi) from quality protein maize were explored. Powdered garlic and ginger individually and mixed at ratio (2 and 4%) resulted in 7 treatments. The microbial loads were enumerated, isolates identified, pH and total titratable acidity were also determined. Ogi with 4% garlic-2% ginger had the lowest microbial count value (19.5×107cfu/ g). Ogi containing 4% garlic-2% ginger had the best effect on microbial loads. 4 Lactic acid bacteria were prominent while 6 yeast isolates were identified. Garlic inhibited the growth of Candida utilis, Candida mycoderma, Candida tropicalis and Candida krusei. Combination of ginger-garlic exerted better synergistic effect and addition of garlic and ginger did not affect important microorganisms involved in the fermentation of ogi. Keywords: Ogi, quality protein maize, sorghum, powdered garlic-ginger, co-fermentation, microbiome

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