The effect of solvent treatment on the chemical composition and organoleptic acceptability of traditional condiments from Nigeria

Three Nigerian condiments from locust bean, melon, and soya bean were prepared by the traditional technique of uncontrolled fermentation and then partly defatted by hexane and di-ethyl ether extraction respectively. Proximate analysis and consumer preference tests were conducted. Results showed that while crude protein, ash and fibre contents remained virtually unchanged, the carbohydrate contents of the treated condiments (derived by difference) increased remarkably. The increase was associated with the significant reduction of about 50% (p=0.05) in lipid contents of the three condiments. The observed solvent effect correlated positively with panelists' preference rating for the treated locust bean and melon condiments. Except with the soya bean condiment, higher mean scores were observed after the solvent treatment for the four sensory attributes assessed. However, condiment-type and treatment notwithstanding, colour and odour appear to critically determine the level of acceptability of condiments.     

Production and chemical evaluation of some food condiments of Nigeria

The study was aimed at investigating the nutrient and tannin composition of fermented legume seeds (oil bean, castor oil bean and African locust bean) used as food condiments in Nigeria. The legume seeds were purchased from local retailers, cleaned and subjected to varied fermentation periods. Standard assay techniques were adopted to analyze the parameters selected for use. The 4-day fermentation period caused the highest increases in protein and tannin and decreases in ash, lipids and non-protein nitrogen (NPN). The pulp of African locust bean had more protein an ash and the oil bean seeds less lipids and NPN. Fermentation times had varied effects on mineral levels. Fermentation for 4 d increased zinc, sodium and phosphorus except sodium for the African locust bean. The pulp had lower Zn and phosphorus than the seed. Fermentation for 4 d offers a greater advantage over other periods for production of nutritious and cheap food condiments in Nigeria.     

Chemical changes during the fermentation of African locust-bean (Parkia filicoidea Welw) seeds for production of ‘Daddawa’

African locust-bean (Parkia filicoidea Welw) seeds were allowed to ferment under natural conditions and the chemical changes occurring during the fermentation were studied. Chemical analysis of fermented and unfermented beans showed a marked decrease in the total sugar content; crude and true protein levels all increased. The results of the chemical analyses indicate that fermentation resulted in protein enrichment of the fermented locust bean (daddaw). Fermentation also imparts a characteristic flavour and odour to the beans.     

Food potentials of some unconventional oilseeds grown in Nigeria — A brief review

A brief review of literature on kernels ofCitrullus andCucumeropsis (egusi melon) species,Telfairia occidentalis (fluted pumpkin),Lagenaria (gourd) species all of Cucurbitaceae family and other oilseeds such asPentaclethra macrophylla (African oil bean),Parkia spp. (African locust bean) both of Mimosaceae family andButyrospermum paradoxum (shea butter) of Sapotaceae family which are grown and widely used as food in Nigeria is presented. The kernels of species of Cucurbitaceae form the bulk of unconventional oilseeds used for food in Nigeria. The nutritional value of some of the kernels and the physicochemical properties and storage stability of the oils obtained from them are discussed. The various consumable forms in which they exist are also described. The problems and prospects of these neglected oilseeds in Nigeria are highlighted.     

Microorganisms associated with natural fermentation ofProsopis africana seeds for the production of okpiye

Okpiye is a food condiment prepared by the fermentation ofProsopis africana seeds. The traditional process for the production and microbiological characteristics of the condiment were investigated. During laboratory fermentation that lasted 96h, the mesquite seeds underwent a natural fermentation that was characterised by the growth of microorganisms to 10⁶–10⁸ cfu/g. Several species of bacteria especiallyB. subtilis, B. licheniformis, B. megaterium, Staphylococcus epidermidis andMicrococcus spp were found to be the most actively involved organisms. However, significant contributions to the microbial ecology were made byEnterobacter cloacae andKlebsiella pneumoniae. Lactobacillus spp were present in low numbers towards the end of the fermentation. The presence ofProteus andPseudomonas spp in traditional fermented samples demonstrate the variability which may exist in the microflora of individual fermented samples. Variations in the important microbial groups show thatBacillus spp were the most prevalent species and occurred until the end of fermentation. Temperature, pH and titratable acidity varied with time and were influenced by the metabolic activities of the microorganisms.     

Improvement of the traditional method of ogiri production and identification of the micro-organisms associated with the fermentation process

Fermented products were developed from different proportions of melon (Citrullus vulgaris schrad) and groundnut (Arachis hypogea) seeds after a 96 hour fermentation period. Proximate analysis, carried out on both fermented and unfermented samples, indicated that only the total carbohydrate content was appreciably reduced by the fermentation process. Micro-organisms responsible for fermentation were identified by gram staining and lactophenol staining, as bacteria and fungi. Identified bacteria were of the Bacillus and Acinetobacter species while the fungi were yeasts, rhizopus and mucor. Samples containing 50–100% melon showed a decrease in pH with increasing fermentation period. Bacteria were largely responsible in samples containing up to 75% groundnuts. Sensory analysis of dried fermented products after fortification with salt, ascorbic acid and flour indicated that they were acceptable.     

链霉菌FB1的发酵产物对5种豆科植物种子萌发的影响

以黄大豆、菜豆、青大豆、黑大豆和红小豆等5种豆科植物的种子为材料,研究了链霉菌FB1的发酵产物对种子萌发的影响.结果表明,链霉菌FB1的发酵产物可以提高4种种子的萌发率,促进后3种种子胚根的伸长,提高所有5种豆科植物种子的简明活力,而且以10倍稀释液的作用最为显著.     

Effect of sample pretreatments on the storability of ground melon ‘egusi’—Colocynthis citrillus L.

In the maintenance of shelf-stability, nutritional and organoleptic properties of ground melon egusi—Colcynthis eitrullus L., vacuum-packaged samples were found to be better than unpackaged samples and samples treated with 0.2% butylated hydroxyanisole (BHA) and 0.02% BHA + 0.045% sodium metabisulphite. After 56 days at 35°C, stored samples showed significant differences (P 0.01) in chemical composition peroxide value (PV), fungal counts and organoleptic attributes. Lipid oxidation and, to a lesser extent, fungal deterioration were responsible for the spoilage of stored ground melon kernel. The dominant fungal flora isolated from stored samples were of the generaPenicillium, Botryodiplodia, Rhizopus andAspergillus.     

An Evaluation of the Microflora Associated with Fermented African Oil Bean (Pentaclethra Macrophylla Bentham) Seeds During Ugba Production

The microorganisms associated with fermented African oil bean (Pentaclethra macrophylla Bentham) seed during ugba production was studied. Only bacteria were isolated from the ugba samples used. Although the bacteria included Bacillus spp., Lactobacillus spp., Staphylococcus spp., Micrococcus spp. and members of the family Enterobacteriaceae, only the Bacillus spp. were found to ferment African oil bean seeds to ugba. Bacillus spp. were the predominant microorganisms present, constituting over 95% of the total microbial population density. An increase in the number of Bacillus cells of about 2 log units daily, which attained a maximum density of log₁₀ 9.00 - log₁₀ 11.90 cfu/g after 3 days was observed. Contrarily, the Lactobacillus spp. increased minimally and attained a maximum value of log₁₀ 4.20 - log₁₀ 6.35 cfu/g within the same period. The Staphylococcus spp., Micrococcus spp. and the members of the family Enterobacteriaceae remained fairly steady in number for 24h, increased slightly till the 3rd day followed by exponential increases which attained maximum values of between log₁₀ 9.20 - log₁₀ 11.00, about the 7th day. Bacillus spp. cells also had the highest protease activities which were significantly (p < 0.05) higher than the values for the other bacterial isolates. The Bacillus spp. responsible for the fermentation of African oil bean seeds to ugba were identified as Bacillus coagulans, B. macerans, B. megaterium, B. pumilis and B. subtilis.     

Comparison of procedures to determine protein content of developing bean seeds (Phaseolus vulgaris)

Micro-Kjeldahl, Lowry and Bradford procedures were compared for determining the protein content ofPhaseolus vulgaris seeds during their development. Micro-Kjeldahl and biuret techniques were also compared with mature seeds of a normal and a genetically-improved bean cultivar. The protein contents of casein and soy protein isolate were as well estimated by these four methods. For many samples of both bean and food protein products large disagreements were found between micro-Kjeldahl and the other three procedures.     

Screening of Dried Plant Seed Extracts for Adiponectin Production Activity and Tumor Necrosis Factor-Alpha Inhibitory Activity on 3T3-L1 Adipocytes

To search for dried plant seeds with potent anti-diabetes activity, we conducted a large scale screening for inhibitory activity on tumor necrosis factor-alpha and facilitating activity on adiponectin production in vitro. These activities in 3T3-L1 adipocytes were screened from ethanol extracts of 20 kinds of dried plant seed marketed in Japan. komatsuna (Brassica rapa var. perviridis), common bean (Phaseolus vulgaris L.), qing geng cai (Brassica rapa var. chinensis), green soybean (Glycine max), spinach (Spinacia oleracea L.) and sugar snap pea (Pisum sativum L.) markedly enhanced adiponectin production (11.3 ~ 12.7 ng/ml) but Japanese radish (Raphanus sativus), edible burdock (Arctium lappa L.), bitter melon (Momordica charantia) and broccoli (Brassica oleracea var. italica) did not (0.9 ~ 2.7 ng/ml). All adiponectin-production-enhancing seeds except spinach (2.7 pg/ml) and okra (Abelmoschus esculentus) (6.6 pg/ml) effectively decreased tumor necrosis factor-alpha levels (0.0 pg/ml). We further examined the effects on free radical scavenging activities in the dried seed extracts. Although scavenging activity correlated well with total phenolic content of samples, no correlation was observed with adiponectin production. These results point to the potential of dried seed extracts as a means to modify the activity of tumor necrosis factor-alpha for the adiponectin production.     

Production of African bread-fruit (Treculia africana) and soybean (Glycine max) seed based food formulations, 1: Effects of germination and fermentation on nutritional and organoleptic quality

Germination and fermentation were investigated as methods of improving the nutritional and organoleptic properties ofsoybean and African breadfruit seed based food formulations.Four products consisting of germinated-fermented soy-breadfruitseeds (GFSB), nongerminated-fermented soy-bread-fruit seeds(NGFSB), germinated-nonfermented soy-breadfruit seeds (GNFSB)and nongerminated-nonfermented soy-breadfruit seeds (NGNFSB)were prepared. Phytic acid contents, in vitro protein digestibilities, protein efficiency ratios (PER), net proteinratios (NPR), flavor, appearance and overall acceptabilitywere evaluated. Germination followed by natural lactic fermentation significantly (p < 0.05) reduced the phytic acid by a factor of 11.6 in NGNFSB compared to reductionfactors of 2.1 and 1.5 in GNFSB and NGFSB, respectively.The in vitro protein digestibility (%), PER and NPR valuesof 73.4, 2.46 and 3.62 for GFSB; 71.1, 2.35 and 3.46 for NGFSB;68.7, 2.16 and 3.41 for GNFSB were significantly (p < 0.05)higher than the 64.7, 1.82 and 2.11 for NGNFSB. The meansensory scores were 5.26–5.67 for GNFSB, 4.66–4.94 forNGNFSB, 4.33–4.80 for GFSB and 4.27–4.34 for NGFSB on a7-point rating scale.     

Phytic acid,in vitro protein digestibility,dietary fiber,and minerals of pulses as influenced by processing methods

The objective of this project was to determine the effect of various types of processing on selected nutrition related parameters of commonly consumed Indian pulses and soybean. Germination reduced the phytic acid content of chickpea and pigeonpea seeds by over 60%, and that of mung bean, urd bean, and soybean by about 40%. Fermentation reduced phytic acid contents by 26–39% in all these legumes with the exception of pigeonpea in which it was reduced by more than 50%. Autoclaving and roasting were more effective in reducing phytic acid in chickpea and pigeonpea than in urd bean, mung bean, and soybean. Germination and fermentation greatly increased the in vitro protein digestibility (IVPD). IVPD was only slightly increased by roasting and autoclaving of all legumes. Germination and fermentation also remarkably decreased the total dietary fiber (TDF) in all legumes. Autoclaving and roasting resulted in slight increases in TDF values. All the processing treatments had little effect on calcium, magnesium and iron contents.     

Favism-inducing toxins in broad beans (Vicia faba) biological activities of broad beans extracts in favism — Sensitive subjects

Ingestion of broad bean seeds will precipitate an acute haemolytic anaemia (favism) in certain sensitive subjects. Aqueous extracts from both fresh and dried mature broad bean seeds, obtained from a favism-endemic area in Iran, were incubated with blood from favism-sensitive and control subjects. Changes in the reduced glutathione content of red blood cells were determined as an index of toxicity. The results showed that:

1. The toxic principles in broad beans were at least partially water soluble.
2. The seed coats of dry mature seeds and the flesh from fresh seeds had low toxicity.
3. The immature whole seeds and the seed coats of fresh mature seeds were toxic.

     

Prolonged tempe-type fermentation in order to improve bioactive potential and nutritional parameters of quinoa seeds

The effect of 40 h solid-state fermentation with Rhizopus oligosporus on selected parameters of white and coloured quinoa was studied, as compared to standard (30 h) product and cooked seeds.The reducing power (RP) and the activity against synthetic free radicals of standard tempe were higher by on average 140% (white) and 64% (coloured quinoa) than that of cooked seeds. The OH scavenging activity was increased by more than 7 fold (white), and over 2 fold (coloured quinoa). Prolongation of the fermentation caused further improvement in this potential, on average by 27% (OH, RP) and 24% (DPPH, ABTS⁺ assays). The soluble phenols i.e. vanillic acid, protocatechuic acid and rutin levels in 40 h tempe were significantly higher than in cooked quinoa. Fermented products contained 470% (white) and on average 150% (coloured quinoa) more riboflavin and 100% more thiamine (white quinoa) than cooked seeds. The levels of total protein, free amino acids and proteins releasable during the in vitro digestion, were improved as a result of 40 h fermentation. The essential amino acids profile of quinoa tempe was consistent with the reference pattern.The prolonged tempe-type fermentation of quinoa can be recommended as a method of the value-added food production.     

Studies on the influence of temperature,relative humidity and microenvironment on the natural fermentation of African oil bean seeds to ‘Ugba’

Studies on the enhancement of the traditional production of Ugba (a protein-rich fermented food) from African oil bean seeds were undertaken by fermenting the bean seeds at different temperatures, relative humidities (RH) and microenvironments. Fermentation was monitored by pH, texture, amino-nitrogen content and the viable cell count of the substrate. The 40 °C, 98% RH or the 130 m high density polyethylene (HDPE) treatment increased the fermentation microflora from ca. 106 CFU/g to ca. 108 CFU/g with high initial changes in pH (5.8–ca. 7.9) and texture (2.0 kg/cm2 to between 1.4 kg/cm2 and 0.9 kg/cm2) in 24 hours. Products with amino-nitrogen contents of between 12.00 mg N/100 g dry matter and 14.00 mg N/100 g dry matter were obtained in 3 days. The cell count of the 30 °C, 80% RH or 70 m treatment increased from 106 CFU/g to ca. 107 CFU/g and the pH increased from 5.8 to about 6.7 with a coincident decrease in the texture value from 2.0 kg/cm2 to about 1.7 kg/cm2 in 24 hours. Products with amino-nitrogen contents between 15.00 mg N/100 g dry matter and 19.2 mg N/100 g dry matter were obtained after 3 days. Changes in the fermentation indicators were not significant at p0.05 (pH and texture) and at p0.01 (amino-nitrogen) after 3 days for the 25 °C, 59.9% RH or 50 m low density polyethylene (LDPE) treatment. Products of fermentation at the combined optimal conditions (80% RH, 35 °C and 70 m HDPE) compared very well with the traditionally fermented products in terms of pH, texture and amino-nitrogen content.     

Aerobic spore-forming bacteria and chemical composition of some Nigerian fermented soup condiments

A total of 97 strains of spore-forming Bacilluswere isolated from 45 samples of three Nigerian fermented condiments, obtained from retail markets located inSouthwestern Nigeria. The isolates were identified asB. subtilis (33%), B. pumilus (19%), B. licheniformis (22%), B. brevis (9%), B.megaterium (12%) and B. polymyxa (5%). Themicrobial load of the condiments showed that the averagecount of spore-formers was between 10⁷ to 10⁹cfu/g. The moisture contents of iru, ugba and ogiri were 57.18%, 46.32% and 42.34%, respectively,while the protein contents were 18.26%, 17.17% and 17.96%. The percentage fat was 29.88%, 40.25% and 44.14% for iru, ugba and ogiri. The ashcontent ranged from 5.8 to 6.1%; a 0.1% titratableacidity and pH values above 7.0 were obtained for the three condiments.     

Evaluation of the selenium and chromium content of plant foods

In the present study the selenium and chromium content of different plant foods such as fruits, greens, flowers, vegetables, dried fruits, spices, condiments, cereals and pulses were analysed. The selenium values for cereals indehiscent vegetables, root vegetables, stem vegetables, pulses, fleshy vegetables, greens, fleshy fruits, condiment seeds, spices and dried fruits ranged between 24.2–32.16, 2.4–18.9, 2.8–21.5, 3.0–32, 48.7–92.5, 1.25–9.5, 3.0–8.2, 2.0–9.4, 6.2–66.2, 6.2–17.5 and 3.5–16.8 g/100 g respectively. The chromium values for the same ranged between 48.2–52.6, 31.0–45, 21.2–25.7, 23.7–62.8, 15.0–43.5, 20.4–65, 14.2–42.1, 14.25–46.7, 58.4–150 and 96–168 g/100 g respectively. Thus dried fruits have the highest chromium content and pulses the highest selenium content.     

Contribution of low molecular weight antioxidants to the antioxidant screen of germinated soybean seeds

Soybean seed of the Mazovia variety (Glycine max) were germinated in the dark at a constant temperature of 25°C up to 168 h (24 h × 7). Changes in content of low molecular weight antioxidants (LMWA) in the course of germination were studied. The analyzed compounds were: total phenolics, soluble proteins, tocopherols (-T, -T, -T, -T), reduced and oxidized glutathione, L-ascorbic acid and L-dehydroascorbic acid. The changes in total antioxidant status (TAS) and the peroxyl radical-trapping capacity (PRTC) of the processed seeds were measured and compared to those of the raw seeds. On the basis of data obtained, the contribution of LMWA to the TAS of raw and germinated soybean seeds was calculated. The results showed a very high molar percentage contribution of phenolic compounds (49.7%) in opposition to glutathione (7.0%), tocopherols (4.0%) and soluble protein (5.7%) to the total TAS of raw soybean seeds. The germination process led to the increased contribution of phenolic compounds (67.7%), soluble proteins (9.3%) and ascorbic acid (4.4%) to the total TAS of germinated seeds and as a result, a decrease in the antioxidant gap was observed compared to the total TAS of raw soybean seeds. This study showed that the contribution of experimentally obtained total PRTC to the total TAS of raw and germinated soybean seeds after seven days ofthe process was 48% and 25.2%, respectively. The PRTC results were comparable to those obtained in TAS only when calculation was done by multiple mean values for content of investigated compounds and their relative potency with respect to Trolox. The PRTC values obtained in this manner were higher than those obtained experimentally indicating that high molecular weight antioxidants as well as are able to quench peroxyl radicals as well as low molecular weight antioxidants. Therefore, calculation of PRTC is a more accurate method that eliminates the puzzling question of unidentified antioxidants shown as the antioxidant gap in the TAS assay.