West African Soft Cheese Research Articles

Extraction of dye sorghum biocolorant for the dyeing of wagashi, a West African soft cheese

We developed a sustainable method to extract the red biocolorant from dye sorghum leaf sheaths for dyeing wagashi, a West African soft cheese. The pigments were extracted using three different solvents: commercial ethanol (method A), sodabi (a local liquor distilled from palm wine; method B) and aqueous alkaline solvent (method C). In methods A and B, a pot still was used to distil and collect the solvent for reuse. The obtained extracts were used to dye wagashi at various concentrations. The yield and colour characteristics of the extracts were evaluated and the physicochemical characteristics of the dyed wagashi were recorded and compared to commercial wagashi sold in the local market. The solvent recovery in methods A and B was 96 % and 47 %, respectively. Extraction of anthocyanin pigments was highest with method A, namely 21 mg mL−1 for total phenolics against 13.4 and 1.64 mg mL−1 for methods B and C, respectively. The colour parameters suggested a similar colour for all the extracts, but the redness index of the extract from method B was significantly higher than that of the other methods. Wagashi dyed with extracts from methods B and C had similar colour characteristics and were comparable to the best-coloured commercial wagashi from the Parakou market based on the chroma and the hue angle values of the chromaticity diagram. Despite the lower colouring power of extracts made by method B, we consider this method the best when taking into account the cost and availability of the solvent. In conclusion, the application of sodabi extract at a dose of 200 mL L−1 is recommended to dye wagashi.

Effect of Parkia biglobosa husk extracts and honey blend on the chemical, sensory and bacterial attributes of traditional West African soft cheese

This study examined the effect of Parkia biglobosa (Locust bean) husk extract and honey blend on the chemical, sensory and bacterial qualities of traditional West African soft cheese. In this study, soft cheese was treated with blends of honey and ethanol extract of P. biglobosa husk at varied levels of 0, 1, 2, 3 or 4% (being percentages of the milk used) for both of the components immediately after coagulation. Seven (7) treatments were studied in a completely randomized design and assessment of the proximate composition and sensory attributes of the cheese was done. The Total Bacterial Count (TBC) was also monitored throughout a five days period. The result revealed that the control cheese was highest in moisture, and ash, but lower in cheese fat content. General acceptability was highest for the cheese curds fortified at 1:3, 2:2 and 3:1 % Honey/P. biglobosa. The 3/1: Honey/P. biglobosa treated cheese showed the highest inhibition rate against bacterial growth. The treatments fortified with 1:3, 2:2 and 3:1 % Honey/P. biglobosa also had the lowest TBC for the days of microbial assay. Seratia odonrifera and Seratia liqueficiens were prominently identified at days 2 and 4 of storage. The study recommend the use of 1:3 , 2:2 and 3/1 % Honey/ P. biglobosa cheese curd fortification as an improvement of the nutritional, sensory and bacterial attributes of West African soft cheese.

Preservative effects of aqueous and ether extracts of Aframomum melegueta on West African soft cheese

The Total Bacterial Count, proximate composition, and sensory evaluation of West African Soft Cheese supplemented with aqueous and ether extracts of the spice Aframomum melegueta (at 0%, 1%, 2% and 3% each) were determined with a completely randomized design. Effects of the spice were monitored for 3 days. The results revealed that 3% concentration of the ether extract of the spice was the most inhibitory (p<0.05) of microbial growth for the duration of the experiment and it also significantly improved the fat, ash and protein contents of the cheese. The study recommended the addition of 3 % ether extract of A. melegueta as an additive to fortify West African soft cheese.Bang. J. Anim. Sci. 2017. 46 (1): 51-56

Prevalence, virulence factor genes and antibiotic resistance of Bacillus cereus sensu lato isolated from dairy farms and traditional dairy products

BackgroundB. cereus are of particular interest in food safety and public health because of their capacity to cause food spoilage and disease through the production of various toxins. The aim of this study was to determine the prevalence, virulence factor genes and antibiotic resistance profile of B. cereus sensu lato isolated from cattle grazing soils and dairy products in Ghana. A total of 114 samples made up of 25 soil collected from cattle grazing farm land, 30 raw milk, 28 nunu (yoghurt-like product) and 31 woagashie (West African soft cheese). Ninety-six B. cereus sensu lato isolates from 54 positive samples were screened by PCR for the presence of 8 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK and entFM), and one emetic gene (ces). Phenotypic resistance to 15 antibiotics were also determined for 96 B. cereus sensu lato isolates.ResultsAbout 72% (18 of 25 soil), 47% (14 of 30 raw milk), 35% (10 of 28 nunu) and 39% (12 of 31 woagashi) were positive for B. cereus sensu lato with mean counts (log10 cfu/g) of 4.2 ± 1.8, 3.3 ± 2.0, 1.8 ± 1.4 and 2.6 ± 1.8 respectively. The distribution of enterotoxigenic genes revealed that 13% (12/96 isolates) harboured all three gene encoding for haemolytic enterotoxin HBL complex genes (hblA, hblC and hblD), 25% (24/96 isolates) possessed no HBL gene, whereas 63% (60/96 isolates) possessed at least one of the three HBL genes. All three genes encoding for non-haemolytic enterotoxin (nheA, nheB and nheC) were detected in 60% (57/96) isolates, 14% (13/96) harboured only one gene, 19% (18/96) whereas 8% possessed none of the NHE genes. The detection rates of cytk, entFM, and ces genes were 75, 67 and 9% respectively. Bacillus cereus s. l. isolates were generally resistant to β-lactam antibiotics such as ampicillin (98%), oxacillin (92%), penicillin (100%), amoxicillin (100%), and cefepime (100%) but susceptible to other antibiotics tested.ConclusionsBacillus cereus s. l. is prevalent in soil, raw milk and dairy products in Ghana. However, loads are at levels considered to be safe for consumption. Various enterotoxin genes associated with virulence of B. cereus are widespread among the isolates.

Effects of different processing methods on some macro-minerals in West African soft unripened cheese

This study was conducted to evaluate the effects of different processing methods on some macro-minerals in West African soft unripened cheese. Milk was processed by blending with high speed mixer for five (5) minutes followed by pasteurization of the blended milk (Blended Pasteurized Milk: BPM). Milk was also fortified with 6 % skimmed milk powder (31.50g skimmed milk in 500ml milk) followed by the pasteurization of fortified milk (Fortified Pasteurized Milk: FPM). Raw milk served as the control. Fresh cheese was coagulated from 500ml milk using 3.75 ml (0.75 % v/v) Calotropis procera medium sized (8 x 15 cm) leaf extract as milk coagulant. Each treatment was replicated four (4) times. Range 0.16 – 0.24 % Ca was obtained. The Ca content of fortified pasteurized milk cheese for the cheeses produced was similar to the control. Fortified pasteurized milk cheese contained significantly higher Na and Cl than raw milk cheese. However, Na and Cl values obtained for FPM cheese and BPM cheese were similar being 0.08 and 0.05, 0.06 and 0.04 % Na and Cl respectively. Milk processing method had little (P > 0.05) effect on the K and Mg content of cheese. It was concluded that raw milk should be used in producing West African soft unripened cheese because milk fortification with blended milk and blending with pasteurization of milk significantly increased the Na content of cheese and this may pose some health risks.Keywords: Blended Pasteurized Milk, Fortified Pasteurized Milk, Raw Milk, Cheese, health risks

Effects of inclusion of varying levels of three natural spices on the mineral composition and organoleptic properties of West African soft unripened cheese (“WARA”)

This study was carried out to evaluate the effect of inclusion of 1%, 2% and 3% bearberry, ginger and onion extracts on the mineral composition and organoleptic properties of cheese. Data obtained were subjected to analysis of variance using a 3x3 factorial arrangement in a Completely Randomised Design.West African Soft Unripened cheese was prepared using 7.5ml Calotropis procera in 500ml of milk . The mineral content of the various cheese samples were determined using Atomic Absorption Spectrophotometer (AAS). A total of twenty (20) respondents were used for sensory evaluation which was carried out on a hedonic scale of 1-9.The results showed that the mineral content of cheese was enhanced by the various inclusion levels of bear berry, ginger and onion. The control consistently had lower values of Ca, PO4, Fe, Mg and Zn. However, organoleptic studies showed that addition of varying levels of bear berry, ginger and onion did not improve the colour, texture, flavor, taste, aroma and general acceptability of cheese. Similar (P>0.05) colour and taste scores of 7.56 and 6.98, 6.91 and 6.40, 7.00 and 6.36, 7.01 and 6.11 were obtained for the control, 1%, 3% bearberry and 3% ginger respectively. All the cheese samples were similarly acceptable except 2% onion which had a significantly (P<0.05) lower score (6.21) than the control. It was concluded and recommended that production and consumption of cheese produced with 1%, 2% and 3% bearberry and ginger and 1% and 3% onion be encouraged as addition of these levels of spices to cheese improved the mineral content of cheese, though it did not enhance its organoleptic properties.Keywords: Cheese, minerals, organoleptic properties, bearberry, ginger, onion

Phenotypic and Genomic Characterization of Enterococcus Species from Some Nigerian Fermented Foods

The gram-positive Enterococci bacteria are generally used as a starter and probiotic cultures in foods. However, they have emerged as one of the leading causes of nosocomial infections worldwide, and this feature is aggravated by the development of antibiotic resistance. Accurate identification of Enterococci at the species level is an important task in food microbiology. In this study, 144 strains of Enterococcus species were isolated from traditional fermented vegetable condiment and West African soft cheese (wara) with the most predominant species being E. gallinarum (75%) followed by E. faecium (14.5%), E. faecalis (7.6%), and E. casselliflavus (2.8%). The strains isolated were characterized and identified using the polyphasic taxonomy approach. Phenotypically, 108 strains were characterized and identified to be E. gallinarum, 21 strains as E. faecium, 11 strains as E. faecalis, and 4 strains as E. casselliflavus. Thirty representative strains were also subjected to genomic characterization, and the result obtained with the phenotypic approach was confirmed. Therefore, the polyphasic taxonomy approach was successful in the accurate identification of the Enterococcus species isolated.

Mini-Review: Theoretical and Onsite Evaluation of Hazard Potentials in the Local Production of Wara; an Indigenous West African Soft Cheese

Mini-Review: Theoretical and Onsite Evaluation of Hazard Potentials in the Local Production of Wara; an Indigenous West African Soft Cheese

Mini-Review: Theoretical and Onsite Evaluation of Hazard Potentials in the Local Production of Wara; an Indigenous West African Soft Cheese

Mini-Review: Theoretical and Onsite Evaluation of Hazard Potentials in the Local Production of Wara; an Indigenous West African Soft Cheese

Eucalyptus Oil and Lemon Grass Oil: Effect on Chemical Composition and Shelf-Life of Soft Cheese

A study was conducted to compare the effect of different levels of Eucalyptus oil (EO) and Lemongrass oil (LO) on the shelf-life of fresh West African soft cheese (wara) in a completely randomized design model for a 28-day period (n=60). The experiment consists of Treatment A (Control, Cheese kept in the whey), Treatment B (75% EO + 25% LO) and Treatment C (50% EO + 50% LO). The results showed similarity in the evaluated parameters (Crude protein, fat and dry matter contents). The ash content was numerically highest in C (5.75%) and least in A (5.00%). The sensory properties were described by positive attributes such as high general acceptability and flavor for Treatments B > C > A. While the microbial evaluation showed least colony unit for Treatment B followed closely by C and A in that order. In conclusion, while both Eucalyptus oil 75% plus 25% lemon grass had a positive impact on the nutritional, sensory and microbial values, whey had no quality to significantly enhance the nutritional, sensory and microbial qualities of West African soft cheese.

A comparative assessment of the nutritional contents of 'wara', a west African soft cheese using calotropis procera and cymopogon citratus as coagulants

The processing line of West African soft cheese varieties (processed with Calotropis procera (Sodom apple) and Cymbopogon citratus (lemon grass) leaf extracts was assessed for nutrient compositions ( nitrogen, crude protein, fat, lactose, moisture content ), pH , total aerobic plate count and trace elements (Fe, Zn, Cu, Mn, Na, Ca, Mg and K) . The percentage of nutrient composition, pH and the total aerobic plate count of microbes were: milk (nitrogen (2.05), protein (2.78), fat (5.33), lactose (1.86), moisture contents (88.75), pH (3.91) and total aerobic plate count (7.3logcfu/ml); Calotropis procera processed cheese (nitrogen (2.00), protein (2.56), fat (4.43), lac tose (1.72), moisture contents (62.89), pH (3.58) and total aerobic plate count (7.34logcfu/ml); Cymbopogon citratus processed cheese (nitrogen (2.01), protein (2.53), fat (4.33), lactose (1.68), moisture contents (63.56), pH ( 3.56) and total aerobic plate count (7.43 logcfu/ml). There were significant differences between the parameters measured in the raw milk and processed cheese at 95% confi dence limit. However, the parameters measured varied slightly in the two cheese varieties ( Calotropis procera and Cymbopogon citratus ). The total aerobic plate counts in milk and cheese were higher than international standards set by C odex alimentarius. Addition of leave extracts (Calotropis procera and Cymbopogon citratus ) increased the total aerobic plate counts but the counts dropped at the curdling point during processing. Cymbopogon citratus cheese had a higher total aerobic plate count than the Calotr opis procera cheese although not at a significant level . There was an increase in Fe, Zn, Cu and Na along the processing line, but a decrease ensued in Mn, Ca, Mg and K. There was no significant difference in the Zn, Cu, Mn, Ca, Mg, K, N, protein, fat and lactose contents of the two cheese types although all trace elements and nutrients assayed were higher in the Calotropis procera processed cheese with the exception of Fe content. The study suggests the use of Cymbopogon citratus leaf extract as a local milk coagulant due to report s of probable health hazard from the use of C. procera . However , further work on improving the yield of cheese when Cymbopogon citratus is used as coagulant is still necessary.

Effect of Temperature and Modified Vacuum Packaging on Microbial Quality of Wara A West African Soft Cheese

Effect of Temperature and Modified Vacuum Packaging on Microbial Quality of Wara A West African Soft Cheese

Optimal levels of calotropis procera leaf and stem juices for optimal yield and consumer acceptance of West African soft unripened cheese (“wara”) in Ibadan, Oyo state.

Optimal levels of Calotropis procera Leaf Juice (CPLJ) and Calotropis procera Stem Juice (CPSJ) that would give the highest cheese yield with good chemical composition and consumer acceptance as determined by the organoleptic properties were assessed. 14 x 500ml of milk from30 White Fulani cows placed in individual pots were inoculated with 0.00, 1.25, 2.50, 3.75 and 5.00ml Calotropis procera Leaf Juice (CPLJ) and 0.00, 1.25, 2.50, 3.75, 5.00, 6.25, 7.50, 8.75 and 10.00ml Calotropis procera Stem Juice (CPSJ) to assess the amount of juice that will give the highest yield, nutritive value and consumer acceptance of the West African soft unripened cheese (“wara”). Cheese Yield (CY) of 25.85% from 7.50ml of CPSJ and 22.62% from 3.75ml of CPLJ were highest (P

Virulence characteristics of food processing relevance in isolates of Listeria monocytogenes and Escherichia coli 0157: H7 strains isolated from 'wara' a West African soft cheese

Three strains of Escherichia coli 0157:H7 and eleven strains of Listeria monocytogenes isolated from West African wara cheese were analysed for cellulose production, fimbriae formation, zetapotential and biofilm formation which are of relevance in food processing. E. coli c produced no fimbria, very low cellulose and significantly lower zetapotential (-3.1) among the three strains. The L. monocytogenes (b) had the highest zetapotential (-39.1) and cellulose production at 24 h of incubation. Next to it was L. monocytogenes (f) which also had a higher cellulose production at 72 h incubation. A positive correlation exists between zetapotential and cellulose production in the E. coli strains (R2 = 0.67) while Listeria monocytogenes strains gave a negative correlation (R2 = -0.08). There was no significant difference in biofilm formation in the L. monocytogenes strains (P < 0.05), however the L. monocytogenes (a) had the highest at 48 h incubation. Weak positive correlation (R²) values of 0.0397, 0.002 and 0.0011 were obtained for 24, 48 and 72 h incubation for Listeria monocytogenescounts (cfu/ml) and cellulose measurements. This study further accentuate and confirmed the presence of E. coli and L. monocytogenes with virulent factors that of relevance to the method of processing in West African soft cheese. The need for an improved hygiene during processing and sale of this product to prevent the transmission of these pathogenic organisms to humans is therefore emphasized. Key words: West African soft cheese, Escherichia coli, Listeria monocytogenes,virulent strains

Consumer acceptability, preference and quality attributes of fresh milk,'Nono'(fermented milk) and West-African soft cheese from cow and goat milk

Consumer acceptability, preference and quality attributes of fresh milk,'Nono'(fermented milk) and West-African soft cheese from cow and goat milk

West African soft cheese ‘wara’ processed with Calotropis procera and Carica papaya : A comparative assessment of nutritional values

The nutritional contents of Carica papaya and Calotropis procera processed cheeses were evaluated. The following nutrients and elements were assayed; fat, protein, moisture, sugar, Zn, Mn, Fe, and Cu and their values were 22.3 and 31.45%, 31.60 and 33.84%, 62.5 and 61.70%, 2.05 and 8.10%, 1.19 and 4.14%, 2.80 and 2.35%, 4.8 and 4.7%, 4.6 and 7.3% for C. papaya and C. procera processed cheeses, respectively. The values obtained for fat, protein, sugar, Zn, and Cu were higher in C. procera processed cheese while Fe and Mn were higher in C. papaya processed cheese. This work therefore showed that even though C. procera have higher nutrient compositions, C. papaya processed cheese could be a good supplement for Fe and Mn in food deficient of the minerals.

Production of wara, a West African soft cheese using lemon juice as a coagulant

As an important protein source for West African consumers, wara cheese made from the leave extract of Calotropis procera has extremely short shelf life of only 2–3 days [Adegoke, G. O., Nse, E. N., & Akanni, A. O. (1992). Effects of heat, processing time, and pH on the microflora, aflatoxin content, and storability of wara, a soft white cheese. Die Nahrung, 36(3), 259–264; Umoh, V. J., & Solomon, O. (2001). Safety assessment and critical control point of milk product and some cereal beverages in Northern Nigeria. In: Proceedings of USDA/USAID/NIGERIA international conference on food safety and security, August 1–3 (pp. 122–127). Ibadan, Nigeria: IITA; Belewu, M. A., Belewu, K. Y., & Nkwunonwo, C.C. (2005). Effect of biological and chemical preservatives on the shelflife of West African soft cheese. African Journal of Biotechnology, 4, 1076–1079; Adetunji, A. O., Alonge, D. O., & Chen, J. (Unpublished). Microbial quality of wara, a southwestern Nigerian soft cheese]. Lemon juice was used in this study as a substitute coagulant during wara manufacture in order to improve the microbial quality of wara. The cheese was manufactured from pasteurized milk inoculated with 10 1 or 10 2 CFU ml −1 of Listeria monocytogenes. Samples of the milk or cheese were taken along the manufacturing steps and during a 5 d storage period at 15 and 28 °C in order to determine the populations of L. monocytogenes, total aerobes, Enterobacteriaceae, and psychrotrophs, as well as mold and yeast. On the 4th day of storage, portions of the un-inoculated control cheese from 28 °C were deep fried in vegetable oil, mimicking the practice of West African local cheese processors. The results showed that L. monocytogenes, at both inoculation levels, did not survive the manufacture of wara. In samples initially inoculated with 10 1 CFU ml −1 of L. monocytogenes, the Enterobacteriaceae counts decreased from the initial 1.78 to 1.00 Log 10 CFU g −1 with the addition of lemon juice, and became undetectable (<1.00 Log 10 CFU g −1) at the curdling point as well as during the 5 d storage period at both temperatures. The total aerobic counts increased from the undetectable level on the 1st day of storage to 7.65 and 3.39 Log 10 CFU g −1, respectively at 28 or 15 °C on the 5th day of storage. The psychrotrophic, as well as the yeast and mold counts increased from the undetectable levels on the 1st day of storage to 7.11 and 5.03 Log 10 CFU g −1, respectively at 28 °C. At 15 °C however, the population of pyschrotrophs remained undetectable throughout the 5 d storage period whereas, the yeast and molds count increased to 3.08 Log 10 CFU g −1 on day 3 before quickly decreasing to the undetectable levels on the 5th day of storage. A similar trend was observed in cheese made from the milk with an initial Listeria inoculation level of 10 2 CFU ml −1. The results of this study showed that lemon juice significantly reduced the populations of the sampled microorganisms, especially the populations of Enterobacteriaceae.

Effect of biological and chemical preservatives on the shelf life of West African soft cheese

The effect of biological extracts on the storage qualities of West African soft cheese was evaluated in a completely randomized design model within a 15-day period. The control and the treated cheeses were stored under ambient temperature and assessed for the pH, titrable acidity, moisture content and crude protein. The pH and titrable acidity rose (P<0.05) with ginger extract preservant. The crude protein and moisture content were increased (P<0.05) by preservation. The ginger extract was found to be the most effective method of reducing microbial load, followed closely by the garlic extract. The ginger extract treatment extended the shelf life of cheese for 15 days. Treatment of West African soft cheese with ginger extract may not markedly alter the nutritional quality but appeared promising as it has a preservative property. Key words: West African soft cheese, biological and chemical extracts, storage qualities.

Effect of biological and chemical preservatives on the shelf life of West African soft cheese

The effect of biological extracts on the storage qualities of West African soft cheese was evaluated in a completely randomized design model within a 15-day period. The control and the treated cheeses were stored under ambient temperature and assessed for the pH, titrable acidity, moisture content and crude protein. The pH and titrable acidity rose (P<0.05) with ginger extract preservant. The crude protein and moisture content were increased (P<0.05) by preservation. The ginger extract was found to be the most effective method of reducing microbial load, followed closely by the garlic extract. The ginger extract treatment extended the shelf life of cheese for 15 days. Treatment of West African soft cheese with ginger extract may not markedly alter the nutritional quality but appeared promising as it has a preservative property.

SENSORY EVALUATION AND NUTRITIVE VALUE OF TEMPE SNACKS IN WEST AFRICA

Two locally-grown legumes namely cowpea and groundbean were processed into tempe, an Indonesian fermented food. Freshly harvested beans for tempe were sliced and either frozen at −20°C and were later blanched or blanched immediately and fried into tempe snacks which were evaluated for their sensory characteristics by three hundred (300) West African panellists. Cowpea and groundbean tempe snacks were comparable in all sensory quality attributes. Despite the low but acceptable scores recorded for the taste, the assessors accepted all the tempe snacks with preference to cowpea tempe snacks. Bean tempe snacks are good sources of protein and energy and were comparable to fried woagachi, a West African unripened soft cheese.