Chemical and Microbiological Quality of Raw Milk Produced by Smallholder Farmers in Zimbabwe

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.

1999 ◽  
Vol 62 (5) ◽  
pp. 499-508 ◽  
Author(s):  
Y.-Y. HAO ◽  
R. E. BRACKETT ◽  
L. R. BEUCHAT ◽  
M. P. DOYLE

The production of toxin by a 10-strain mixture of proteolytic Clostridium botulinum in fresh produce packaged in polyethylene films with different oxygen permeability was determined. Broccoli florets, shredded carrots, and green beans inoculated with approximately 102 C. botulinum spores per g were placed in bags (1.4 kg per bag) composed of four films with different oxygen transmission rates (OTRs). Broccoli was packaged in bags with OTRs of 3 (7,000 cm3/m2/24 h) and 4 (16,000 cm3/m2/24 h), and green beans were packaged in bags with OTRs of 2 (6,000 cm3/m2/24 h) and 4. Broccoli and green beans in bags were compressed and heat-sealed. Shredded carrots were packaged in bags with OTRs of 1 (3,000 cm3/m2/24 h) and 3 and vacuum-sealed. Produce was stored at 4, 13, and 21°C for up to 27 (broccoli) or 28 (carrots and green bean) days and analyzed periodically. At each sampling time, gas composition within the bags, pH of the produce, microbial populations (total aerobic and anaerobic microorganisms, lactic acid bacteria, psychrotrophic bacteria, yeasts, and molds), and the presence or absence of botulinal toxin were determined. Packaging material affected the quality of vegetables, especially broccoli stored at 4 and 13°C. For example, broccoli was scored as “good” after 22 days at 4°C when it was packaged in film with higher gas permeability (OTR of 4), whereas broccoli appeared to be in “poor” condition when packaged in film with lower gas permeability (OTR of 3). With the exception of lactic acid bacteria, packaging material did not noticeably influence the growth of microorganisms. Lactic acid bacteria grew better in broccoli packaged in bags with an OTR of 3 than in those with an OTR of 4 at all temperatures. Botulinal toxin was detected in broccoli packaged in bags with an OTR of 3 and stored at 13°C for 21 days and in those with an OTR of 4 and 3 and stored at 21°C for 10 days. All toxic samples were visibly spoiled. Toxin was not detected in produce packaged under any other test conditions.


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.


Author(s):  
Nesrin Kaval ◽  
Nilgün Öncül ◽  
Zeliha Yıldırım

In this study, the microbiological quality of traditionally produced Bez Sucuk in Tokat and its vicinity was investigated. For this purpose, 30 Bez Sucuk samples obtained from butchers, producers of Bez Sucuk, were analyzed for total count of mesophilic aerobic bacteria, lactic acid bacteria, yeasts-moulds, total coliform, fecal coliform, Staphylococcus aureus, Bacillus cereus, and Cl. perfringens. Also, the presence of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. were investigated in all samples. pH and water activity of the samples were determined. As the result of the analysis, the counts of the microbiological parameters investigated were found as follows: total mesophilic aerobic bacteria 3.5×106-4.23×109 CFU/g, lactic acid bacteria 5.55×105-2.45×109 CFU/g, yeasts and moulds 2.50×103-6.90×109 CFU/g, total coliform


1990 ◽  
Vol 53 (3) ◽  
pp. 255-257 ◽  
Author(s):  
R. E. BRACKETT

Fresh bell peppers were individually shrink-wrapped in film (SW), sealed in gas-flushed (5% O2, 10% CO2, 85% N2) film (GP) pouches, or stored unpackaged in cardboard packing crates (CN). All samples were stored at 13°C and changes in populations of total aerobic microorganisms, yeasts and molds, members of Enterobacteriaceae, and lactic acid bacteria were determined. In addition, overall sensory quality, color changes, and surface pH were monitored. SW peppers developed higher populations of total aerobic microorganisms, yeasts and molds, and Enterobacteriaceae than did CN peppers, but populations of other groups of microorganisms were similar. Color and surface pH of peppers did not differ in any of the treatments. SW and GP peppers remained unspoiled at least 6 weeks, whereas CN peppers spoiled in 3 weeks.


2017 ◽  
Vol 14 (2) ◽  
pp. 587-591
Author(s):  
K. Mchiouer ◽  
S. Bennani ◽  
N. Sh. El-Gendy ◽  
M. Meziane

ABSTRACT: The aim of this study is to determine the microbiological quality of raw cows’ milk of Oujda city. Raw milk samples are collected randomly between June 2014 and May 2015 from 20 Mahlaba (dairies) for microbiological evaluation. The samples are analyzed to determine total mesophilic aerobic bacteria (TMAB), total coliform, fecal coliform, staphylococcus aureus, fecal streptococci, proteolytic bacteria and lactic acid bacteria. The results of bacterial count showed that there is a variation between all the milk samples and a period effect is also observed. The mean counts of total mesophilic aerobic bacteria from all sale points are between 1.76×106 and 40.17×106 CFU/ml. Milk samples reveled counts total coliform and fecal coliform ranging from 0.58×105 to 11.10×105 CFU/ml and from 0.60×103 to 14.64×103 CFU/ml, respectively. Staphylococcus aureus are also detected in all samples with counts ranging from 0.35 ×103 to 3.08×103 CFU/ml. Fecal streptococci are found in all milk samples, at counts ranging from 0.16 ×102 to 2.18 ×102 CFU/ml. And finally, proteolytic and lactic acid bacteria are between 0.3×103 and 2.86×103 CFU/ml and 2.37×106 and 24.14 ×106 CFU/ml respectively. These results indicate a lack of compliance with good manufacturing practice at milking, collection and transportation of raw milk.


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.


2019 ◽  
Vol 20 (6) ◽  
pp. 489-496 ◽  
Author(s):  
Anna Chlebowska-Śmigiel ◽  
Katarzyna Kycia ◽  
Katarzyna Neffe-Skocińska ◽  
Marek Kieliszek ◽  
Małgorzata Gniewosz ◽  
...  

Background: Pullulan can partially or completely replace starch or fat, thanks to which it can be used for the production of dietetic food. It allows you to maintain the desired consistency, and increases the viscosity of the product. Objective: Therefore, an attempt was made to produce yogurts with pullulan addition and determine the effect of its presence on the number of LAB, pH change, titratable acidity, and sensory quality of yogurts during storage at 4°C for 28 days. Method: The effect of addition of 0; 1.0 and 2.0 % w/v pullulan as a yogurt ingredient on the changes in pH, acidity, LAB number, and sensory quality of yogurt during storage at 4°C for 28 days was examined. Results: Pullulan did not affect yogurt pH, but the addition of 2.0 % w/v pullulan increased the acidity of yogurt as compared to that of the control yogurt. A statistically significantly higher total number of Lactobacillus, by approximately 1 logarithmic cycle, was found in yogurts with pullulan than in the control yogurt on the 28th day of storage. The yogurt with 1.0% w/v pullulan addition showed better sensory characteristics than that with 2.0% pullulan w/v addition. Conclusion: The conducted research proved that the presence of pullulan in the culture medium stimulates the growth of selected lactic acid bacteria and influences their fermentation capacity. The use of 1.0 % w/v pullulan during the production of yogurts allowed to obtain a sensorically acceptable product, it had a protective effect on the number of lactic acid bacteria during 28 days of refrigerated storage of yogurt.


2021 ◽  
Vol 5 (1) ◽  
pp. 28-35
Author(s):  
Miroslava Kačániová ◽  
Jakub Mankovecký ◽  
Lucia Galovičová ◽  
Petra Borotová ◽  
Simona Kunová ◽  
...  

Abstract The safety of plant-based food of plant origin is a priority for producers and consumers. The biological value of food products enriched with herbal ingredients is getting more popular among consumers. The present study was aimed to evaluate microbiological quality of grape juice enriched with medicinal plants. There were two varieties of grapes -Welschriesling and Cabernet Sauvignon and six species of medicinal plants used for the experiment: Calendula officinalis L., Ginkgo biloba, Thymus serpyllum, Matricaria recutita, Salvia officinalis L., and Mentha aquatica var. citrata. A total of 14 samples of juice were prepared and two of them were used as controls and 12 samples were treated with medicinal plants. Total microbial count, coliforms, lactic acid bacteria and yeasts and microscopic fungi for testing the microbiological quality were detected. All the samples were negative for lactic acid bacteria. There were neither coliform bacteria nor yeast and fibrous microscopic fungi present in some of the treated samples apart from the control samples. Coliform bacteria of 1 log cfu/mL were detected during the first testing and identified Proteus vulgaris in the control sample of grape juice of the variety Welschriesling. The yeast of the genus Candida was present in 2 log cfu/mL and it was detected during first and second testing in the control sample of Cabernet Sauvignon, unlike the other samples. The sample of grape juice with the addition of sage had the most significant inhibitory effect on total count of bacteria. The most common microorganisms in all samples were Bacillus cereus and Acinetobacter johnsonii, however, those microorganisms were absent during second testing due to the action of naturally occurring antimicrobials in the grapes.


2018 ◽  
Vol 11 (4) ◽  
pp. 1435-1442
Author(s):  
Caner E. Ozyurt ◽  
Esmeray Kuley Boga ◽  
Ali Serhat Ozkutuk ◽  
Yılmaz Ucar ◽  
Mustafa Durmus ◽  
...  

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