Structure,composition and functional properties of storage proteins extracted from bambara groundnut (Vigna subterranea) landraces

Bambara groundnut is a protein‐rich traditional legume. In this study, storage proteins were isolated from three bambara landraces. Bambara protein revealed four major protein bands: one broad band at 55 kDa, two medium bands at 62 kDa and 80 kDa and a high molecular weight (HMW) protein at 141 kDa. The vicilin (7S) subunits with molecular weight of 55 kDa and 62 kDa were major fractions in bambara storage proteins. Bambara proteins showed two endothermic peaks ranging from 64 to 69 °C and 76 to 90 °C, respectively. Bambara protein isolates had well‐defined tertiary and secondary structures, respectively, at pH 3.0, and this well‐defined structure decreased slightly at higher pH values. The isolates revealed a strong secondary structure dominated by α‐helical conformation. Foaming capacities of bambara proteins were dependent on pH with maximum percentage FC observed at pH 3.0, while the emulsion activity increased with increasing pH for all the isolates. Vicilin (7S) fraction seems to be the major storage protein fraction of bambara. Bambara proteins could serve as excellent ingredients for the formulation of food foams and emulsions.     

The synthesis and photophysicochemical behaviour of novel water-soluble cationic indium(III) phthalocyanine

The syntheses and characterization of 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) and quaternized 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) are described. The ground state electronic absorption spectra, photophysics and photochemistry of both dyes in DMSO as well as that of the quaternized compound in aqueous solution are also presented. A comparison of the photophysical and photochemical parameters of the two dyes revealed that quaternized 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) was a better photosensitizer than its unquaternized counterpart. The quantum yield values of fluorescence (Φ_F), triplet state formation (Φ_T) and singlet oxygen formation (Φ_Δ) for the cationic dye were found to be 0.03, 0.68 and 0.66 respectively in DMSO; these values were higher than those for 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III), which exhibited values of 0.02, 0.66 and 0.63, respectively in DMSO. The values for the cationic dye in aq. solution were 0.02, 0.59 and 0.56 respectively, suggesting that the water-soluble quaternized 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) offers potential as a photosensitizer in photodynamic therapy treatment.     

Development and sensory acceptability of crackers made from the big-eye fish (Brachydeuterus auritus)

The big-eye (Brachydeuterus auritus), which is present in a large biomass in the Gulf of Guinea, is generally considered an underutilized fish species. In an attempt to add value, it was used to complement cassava starch (Manihot esculenta Crantz) to produce fish crackers. Three levels of fish (40%, 50%, and 60%) and three levels of starch (60%, 50%, and 40%) were used in the formulations. Proximate analyses and sensory evaluations were carried out. The protein, fat, and ash contents increased with an increase in the proportion of fish. The sensory evaluation tests showed that the most acceptable formulations for the crackers were obtained using 50% fish/50% starch and 40% fish/60% starch combinations. The linear expansion of the fried crackers increased with the increased proportion of fish. Production of fish crackers, apart from its appeal for increasing protein intake, has the potential to support a small regional snack factory in a developing economy.     

Effect of substituting pork backfat with rind on quality characteristics of pork sausage

A study was conducted in which pork backfat in pork sausage was replaced with rind at 0, 33, 66 and 100% levels. The high moisture and high protein content of rind consequently influenced the moisture and protein content of the final products. The fat level decreased with increase in the level of rind in the sausage. The lowest fat content of 7.99% was recorded on batch 4 sausage with 100% rind replacement level. Replacement of pork backfat with rind decreased refrigeration and cooking weight losses. The values obtained for sensory properties decreased with increase in the level of rind in the sausage. Up to 66% pork backfat can be replaced with rind in pork sausage without adverse effect on processing yield.     

Fungi and mycotoxins in cowpea (Vigna unguiculata L) on Nigerian markets

ABSTRACT

In this study, 81 samples of two cowpea varieties (brown: 54; white: 27) collected from various markets in southwestern Nigeria were examined for fungal and mycotoxin contamination. Moulds belonging to Aspergillus, Fusarium, and Penicillium were recovered from 99% of the samples. In both cowpea varieties, Aspergillus (52–53%) dominated Fusarium (29–30%) and Penicillium (17–20%). The interactive effect of cowpea variety and sampled location was significant (p = .013) on the occurrence of Fusarium species. Aflatoxins were detected in one brown and two white cowpea samples at concentrations reaching 209 and 84 µg/kg, respectively. Additionally, beauvericin was found in two samples of each cowpea variety, albeit at low concentrations. Cowpea presents as an alternative vegetable protein source to groundnuts in household nutrition with respect to mycotoxin contamination. Simple techniques to prevent mycotoxins in dry cowpeas are discussed.