Evaluation of Yield and Physicochemical Quality of Pentadesma butyracea Butter Obtained by Different Traditional Extraction Methods in Ghana.

Pentadesma butyracea seed butter or fat (PBSB) is a vegetable fat extracted from the seeds of the P. butyracea plant. The butter has potential use in the food, pharmaceutical, and cosmetic industries. The study investigated traditional PBSB processing methods in Ghana and evaluated their effects on yield, physicochemical parameters, and fatty acid composition. Four traditional extraction methods were identified and evaluated, and these methods are direct wet extraction of PBSB from a fresh mixture of the seed paste and water (DEW); wet extraction of PBSB from a 12-hour fermented mixture of the seed paste and water (FWO); direct wet extraction of PBSB from a fresh mixture of the seed paste, salt, and water (DES); and wet extraction of PBSB from a 12-hour fermented mixture of the seed paste, salt, and water (FSO). Results of physicochemical properties of the PBSB samples showed moisture content of 0.06-0.07%, free fatty acid of 1.38-2.43%, iodine value of 56.50-56.85 Wijs, peroxide value of 5.58-8.52 mEq/kg, relative density of 0.91, refractive index of 1.462-1.464, percent impurities of 0.015-0.017%, saponification value of 165.57-178.02 mg KOH/g, and percent unsaponifiable matter of 2.60-3.18%. The PBSB yield varied in the range of 21.68-26.97%, with the highest average butter yield observed for FWO. Seventeen fatty acids were characterized in the PBSB samples, and they included ten saturated fatty acids, five monounsaturated fatty acids, and two polyunsaturated fatty acids. Key fatty acids found in the PBSB samples were oleic acid (51.21-51.31%), stearic acid (43.22-43.33%), palmitic acid (2.91-3.07%), linoleic acid (0.49-0.51%), linolenic acid (0.12-0.20%), and arachidic acid (0.14-0.15%). PBSB samples produced by the various traditional extraction methods in Ghana recorded similar physicochemical characteristics as unrefined shea butter per the Regional Standard for Unrefined Shea Butter (CXS 325R-2017) as well as Cook Brand Margarine, a common commercial baking fat, and thus, their potential food application such as an alternative shortening/ingredient could be explored in a future study.

Development of yoghurt incorporated with beetroot puree and its effect on the physicochemical properties and consumer acceptance.

Background: Yoghurt is one of the most popularly consumed fermented products which provides several nutritional benefits. Yoghurt products often include flavour and colour additives however, growing awareness of the risks associated with synthetic food additives has necessitated the need to explore more natural colour and flavour as food additives. Methods: This study evaluated the effect of beetroot puree as flavouring and colourant in yoghurt production and quality. To develop the yoghurt product, incubation time and proportion of beetroot puree were optimized based on the resulting pH, titratable acidity, colour, and viscosity using response surface methods. Results: Optimum yoghurt formulations were obtained in products containing 2 %, 2.03 % and 8 % beetroot puree following an incubation of 2.5h. Increasing beetroot puree did not affect the pH and titratable acidity of the yoghurt samples but slightly influenced the viscosity of the yoghurt. The colour of yoghurt was mainly affected by the puree concentration. A consumer acceptance test was conducted on the optimized products compared to a control sample without beetroot. Yoghurt incorporated with 8 % beetroot puree was the least preferred with a mean score of 6.08, whereas yoghurt incorporated with 2.03 % beetroot puree was the most preferred (7.42), with a higher acceptance than the control (7.28). Conclusion: /Implications for industry: Findings from the study provide evidence for exploration of beetroot yoghurt as a natural product alternative to the use of synthetic flavour and colour additives in yoghurt.

In vitro properties of potential probiotic lactic acid bacteria originating from Ghanaian indigenous fermented milk products.

Fermented milk products are a major source of health-promoting microorganisms known as probiotics. To characterize the probiotic properties of lactic acid bacteria isolated from Ghanaian traditionally fermented milk, thirty (30) isolates comprising Enterococcus faecium (1), Lactobacillus fermentum (14), Lb. plantarum (2) and Pediococcus acidilactici (13) identified by 16S rRNA gene sequencing, were tested for survival at low pH (2.5) and bile salts (0.3% (w/v)), hydrophobicity, co-aggregation, auto-aggregation and antimicrobial activities against selected pathogens. Safety of potential probiotic bacteria was assessed by hemolytic activity on blood agar and susceptibility to nine different antibiotics. Majority (90%) of the strains showed survival rates above 80% at pH (2.5) and in bile salts (0.3% (w/v)). Hydrophobicity ranged from 5 to 61% while cell auto-aggregation ranged from 41 to 80% after 24 h. Co-aggregation with E. coli (3.7-43.9%) and S. Typhimurium (1.3-49.5%) were similar for the LAB strains at 24 h. Cell- free supernatants of all LAB strains inhibited E. coli while S. Typhimurium was not sensitive to cell-free supernatants of five Pd. acidilactici strains: OS24h20, OS18h3, OY9h19, OS9h8 and 24NL38. None of the LAB strains showed ß-hemolysis but 38% of strains showed α-hemolysis. Susceptibilities to antibiotics were strain-specific; only four strains, two Lb. fermentum and two Pd. acidilactici were susceptible to all nine antibiotics tested. Based on high survival rates in bile salts, low pH and generally good hydrophobicity, auto-aggregation, co-aggregation and inhibitory activities, 15 out of 30 strains tested were considered qualified candidates for development of probiotic cultures for fermented milk products in sub-Saharan Africa.

Effect of pretreatment on physicochemical, microbiological, and aflatoxin quality of solar sliced dried ginger (Zingiber officinale Roscoe) rhizome.

Pretreatment of fruit and vegetables is necessary to reduce microbial proliferation and to preserve color of the produce. The effect of drying and pretreatment with potassium metabisulfite (KMBS) of concentrations 0.0%, 0.1%, 0.15%, 0.2%, and 1.0% and blanching at 100°C and 50°C using a tent-like concrete solar (CSD) dryer as compared to open-sun drying (OSD) of yellow ginger rhizomes was investigated using routine methods. The total color change and residual sulfur dioxide (SO2) were analyzed. KMBS reduced the yeast and mould load significantly from 3.6 × 104 ± 1.4 × 103 CFU/g in 0.0% (control) to <10 CFU/g in 1.0% KMBS and 100°C blanched fresh samples. Drying of the fresh samples for 5 days increased the yeast and mould load of all the treatments to as high as 1.15 × 105 ± 2.12 × 104 CFU/g for the 1.0% KMBS. Overall, the CSD had fewer microbial loads than the OSD but it was not significant. Aflatoxins and Salmonella sp. were not detected in any of the samples. The sulfur dioxide residue (SO2) for KMBS pretreated samples increased as the concentration of KMBS increased with the CSD retaining slightly higher amount than the OSD. The total color change index increased with increase in KMBS, and drying further increased the total color change index. On the whole, the blanched samples had the least color change among the pretreatments with 100°C CSD showing the least change among the dried samples.

Potential health benefits of water yam (Dioscorea alata).

Yam is the third most important root and tuber crop in the tropics but few species are grown as health food and/or for medicinal purposes. To ascertain the potential health benefits and alternate usage of the species, 20 varieties of Dioscorea alata (water yam) were investigated for their total dietary fiber (TDF), dry matter and amylose contents as well as selected minerals in comparison with Dioscorea rotundata, the preferred species in yam-growing areas. The TDF content varied widely ranging from 4.10 to 11.00%. The dry matter composition ranged from 19.10 to 33.80% and amylose was from 27.90 to 32.30%. In mg kg(-1), mineral contents of the varieties were from 10.10-17.60 for Zn, 10,550-20,100 for K, 83-131 for Na, 260-535 for Ca, and 390-595 for Mg. The results show significant differences (P > 0.05) among the test varieties in all the parameters determined. Generally, the test varieties had lower dry matter but higher amylose contents. TDF contents of the varieties were higher than that reported for brown rice while two varieties had comparable values to whole wheat flour. Identified varieties with higher amylose and TDF contents could be of use to diabetics and other health conscious individuals due to their slower absorption rates. Moreover, the low sodium but high potassium and TDF contents indicate the possible preventive role that D. alata could play in managing related chronic diseases. This shows the potential use of D. alata as a functional food to supplement the fiber and mineral needs of consumers. Thus, there is a need to exploit its use in food fortifications and formulations.