Chemical composition of kale as influenced by dry vermicast, potassium humate and volcanic minerals.

Biofortification using agronomic practices can be used to improve the nutritional quality of food crops. Three natural media amendments (dry vermicast, potassium (K)-humate and volcanic minerals) were assessed under greenhouse conditions to determine the effects on the chemical composition of kale (Brassica oleracea L. var. acephala 'Ripbor'). The results indicated that K-humate had low pH, while the volcanic minerals had high pH. Plants grown in the dry vermicast amended media had the highest levels of macronutrients and micronutrients except for zinc and iron. However, the glycolipid: phospholipid ratio was lower in kale plants cultivated in dry vermicast compared to plants cultivated in the volcanic minerals or K-humate. Conversely, plants cultivated in the dry vermicast had enhanced levels of polyunsaturated fatty acids. The omega-3 fatty acid content was significantly (P < 0.05) higher in plants cultivated in dry vermicast and potassium humate, while the omega-6 fatty acids were unaffected by media amendments. Dry vermicast was the most effective at increasing plant tissue oleic acid content. The total phenolic content and antioxidant capacity were highest in plants treated with K-humate, but lowest in the dry vermicast treated plants. In conclusion, dry vermicast proved to be the most effective in enhancing the phytochemical composition of kale 'Ripbor'. These results suggest dry vermicast could be a potential target natural media amendment for biofortifying kale plants during cultivation.

Development and quality characteristics of shelf-stable soy-agushie: a residual by-product of soymilk production.

A process was developed for the production of a high-protein food ingredient, soy-agushie, from the residual by-product of soymilk production. The product, with a moisture content of about 6%, was evaluated for its quality characteristics and performance in traditional dishes. The protein content was about 26% with similar amino acids content as that of the whole soybean. Lysine remained high in the dehydrated product (6.57 g/16 g N). While over 60% of the original B vitamins content in the beans was extracted with the milk, high proportions of the minerals were found to be retained in the residual by-product. The process adequately reduced the trypsin inhibitor levels in the beans from 25 to 1.5 mg/g. High sensory scores were obtained for recipes developed with soy-agushie in traditional dishes. The scope of utilization of the soy-agushie could be widened to include several traditional foods and bakery products for maximum nutritional benefits.

Volatile compounds profile and sensory evaluation of Beninese condiments produced by inocula of Bacillus subtilis.

BACKGROUND: Three Beninese food condiments (ABS1(24h), IBS2(48h) and SBS3(48h)) were produced by controlled fermentation of African locust beans using inocula of pure cultures of Bacillus subtilis, BS1, BS2 and BS3, respectively. Quantitative and qualitative assessments of the volatile compounds in the condiments produced have been performed using the Likens-Nickerson simultaneous distillation-extraction method and GC-MS analysis, followed by a sensory evaluation in comparison with the spontaneously fermented condiments. RESULTS: A total of 94 volatile compounds have been found including 53 compounds identified in relatively high concentrations and were subdivided into seven main groups with the predominance of four major groups: pyrazines, aldehydes, ketones and alcohols. Compared to the spontaneously fermented condiments, volatile compounds identified in controlled fermented condiments have been found in high number and in concentrations which varied according to the inoculum of B. subtilis used. The condiments produced with starter cultures scored significantly (P < 0.05) higher for odour than the spontaneously fermented condiments. But the overall acceptability (7/10) of the two types of condiments was similar. CONCLUSION: The investigated B. subtilis, BS1, BS2 and BS3 can be considered as potential starter cultures for the fermentation of African locust beans to produce good quality of Beninese food condiments.

Microencapsulation in genipin cross-linked gelatine-maltodextrin improves survival of Bifidobacterium adolescentis during exposure to in vitro gastrointestinal conditions.

To improve survival during exposure to adverse conditions, probiotic Bifidobacterium adolescentis 15703T cells were encapsulated in novel mono-core and multi-core phase-separated gelatine-maltodextrin (GMD) microspheres where the gelatine (G) phase was cross-linked with genipin (GP). Microscopy showed that encapsulated cells were exclusively associated with maltodextrin (MD) core(s). Small (average diameter 37 microm) and large (70 microm) GMD and G microspheres were produced by modulating factors (e.g. mixing speed, surfactant, GP and G concentrations) affecting the size, structural stability and phase-separation. In vitro sequential gastro-intestinal (GI) juice challenge experiments revealed increased survival of cells encapsulated in GMD ( approximately 10(6-7) cfu mL(-1)) and G (approximately 10(5) cfu mL(-1)) microspheres as compared to free cells (approximately 10(4) cfu mL(-1)). In GMD microspheres, the bacteria derive energy from MD to survive during exposure to acid and bile salts. In conclusion, the novel food grade GMD microencapsulation formulation was shown to protect probiotic bifidobacteria from adverse conditions.

Effect of boiling and roasting on the fermentation of soybeans into dawadawa (soy-dawadawa).

Soybeans which had initially been dehulled by either boiling (boiled/dehulled) or roasting (roasted/dehulled) before peeling, were cooked and fermented into dawadawa, a traditional food condiment. The micropopulation, enzymatic activities, proximate composition, amino acid, and aroma profiles of the two types of soybean dawadawa were evaluated during fermentation. Only minor differences were found in the microbial profiles of the two types of soy-dawadawa. Although boiled/dehulled soy-dawadawa initially had lower microbial counts, it recorded higher counts at the advanced stages of fermentation. Proteolytic and amylolytic Bacillus species including Bacillus subtilis, Bacillus pumilus, Bacillus licheniformis, Bacillus cereus, and Bacillus firmus dominated the micropopulation of the two types of soy-dawadawa with Bacillus subtilis accounting for about 50% of the Bacillus species in all samples. Lactic acid bacteria and yeasts occurred in low numbers in the two types of soy-dawadawa. The proximate composition of the two types of soy-dawadawa were similar, and their contents of moisture and protein increased whilst fat and ash decreased during fermentation. Both types of fermenting soy-dawadawa recorded similar levels of alpha-amylase activity, but boiled/dehulled soy-dawadawa showed slightly higher protease activity. The levels of isoleucine, leucine, lysine, phenylalanine, arginine and proline increased significantly with fermentation time in both types of soy-dawadawa. With respect to differences in their aroma profiles, hexanodecanol, octadecyl acetate, 1,2-dimethyl benzene, tetradecene, (E)-5-eicosene, cyclohexadecane, and hexacosane were found only in the roasted/dehulled samples, whilst 1,2-ethanediol, ethyl acetate, dimethyl disulfide, cyclotetradecane, decene, indole , 2 butyl-octenal, acetophenone, and toluene were found only in the boiled/dehulled samples. A market focus group showed preference for roasted/dehulled soy-dawadawa over boiled/dehulled soy-dawadawa. Apart from the volatile aroma compounds, the biochemical and microbiological profiles of the two types of soy-dawadawa showed only minor differences and were also similar to the profiles reported for African locust bean dawadawa.