The influence of blanching, anti-browning agent and processing time on some physico-chemical properties and appearance of green peppers (Capsicum sinensis) during canning

Central Composite Rotatable Design (CCRD) was used to generate twenty combinations of these factors: blanching time, processing time and sodium metabisulphite concentration. The optimized conditions were then adapted for the canning process of green pepper. Blanching time ranged from 0-1 min whereas processing time and sodium metabisulphite concentration ranged from 10-30 min and 0-0.2%, respectively. The canned products were analyzed for physico-chemical qualities using standard analytical methods. Results obtained from various physico-chemical analyses showed variable trends and influences of the linear, quadratic and exponential interactions on the measured quality indices such as pH of the drained liquid, drained weight of the canned product, leached solids and colour of the canned products. The results showed significant (p.0.05) quadratic effect of sodium metabisulphite as well as linear effect of blanching time on the drained weight of the canned green pepper. Generally, the pH of the medium decreased (increased acidity) with increasing processing time, which was also positively associated with the extent or amount of leaching. Additionally, all three factors were observed to have affected (to variable extent) the colour of the canned products. Blanching and processing times also affected the degree of browning. There was a strong significant (p.0.05) influence of the quadratic factors of blanching time, processing time and sodium metabisulphite concentration on the colour properties (a-values, b-values and L-values) of the canned products. Statistical analysis showed significant (p.0.05) linear effects of blanching time and sodium salt concentration as well as the combined effect of both factors on all the colour properties. All the studied parameters had significant  regression coefficients (p.0.05) suggesting the studied parameters  contributed significantly to the observed changes. Colour of the canned  products changed from green toward redness with increasing blanching time at all concentrations of sodium metabisulphite. Optimal processing  combination of 0 min blanching time, 10 min processing time and sodium metabisulphite concentration of 0.2% produced a highly acceptable canned pepper product with preferred physico-chemical and appearance properties.Key words: Canning, pepper, blanching, antibrowning agent

Influence of fermentation and cowpea steaming on some quality characteristics of maize-cowpea blends

Fermentation and cowpea steaming can be used to improve the protein quality and quantity of fermented maize dough. In the production of maize-cowpea blends, it is important that the quality characteristics are evaluated to determine their functionality in the products. A 5x4x2x2factorial experiment with cowpea level, fermentation time, cowpea steaming time and fermentation method as the variable was performed. The cowpeas were dehulled, steamed, dried at 65EC for 24 hours and milled into flours. Maize was soaked in water (18 hours), drained and milled into flour. The maize-cowpea blends were made into a 50% moisture dough, fermented for the specified periods, dried at 65EC and milled into flour. Samples were evaluated for pH, titratable acidity, water absorption and sugars. The pH and titratable acidity of the samples were affected by fermentation time, steaming time, and the levels of cowpeas in the blend. Cowpeas was the main source of glucose/galactose.Fermentation caused a reduction in stacchyose and glucose/galactose. The mixing of cowpea flour with fermented maize dough prior to drying (single component fermentation) gave similar effects on sugar concentrations as detected in the co-fermented samples (multi-component fermentation).Fermentation and steamed cowpea fortification can be used to produce high protein fermented cereal foods with reduced anti-nutritional factors

Effects of cowpea fortification and the level of ripeness of plantain on the nutritive value of plantain based snack foods

To investigate effects of cowpea addition and level of ripeness of plantain on the nutritional and sensory characteristics of Kaklo and Ofam in Ghana, A 2X4 factorial experiment with firm and soft ripe plantain and cowpea fortification of 0, 10, 20 and 30% was designed. The proximate composition and acceptability of products using a 7-point hedonic scale were evaluated. With the addition of 30% cowpea, the protein content of the Kaklo from the firm ripe and soft ripe plantain increased from 2.92% to 7.32% and 3.65% to 8.05% respectively, whilst the protein of the Ofam from the firm and soft ripe plantain also increased from 3.80% to 8.45% and 3.75% to 8.15% respectively. The 10% fortified Kaklo and Ofam werethe most acceptable. The cowpea addition significantly affected the nutritional value of the Kaklo and Ofam. To obtain an acceptable cowpea fortified plantain-based snack, the fortification should be done at10%

Composition of unfermented, unroasted, roasted cocoa beans and cocoa shells from Peninsular Malaysia

Composition of cocoa beans depends on origin and cocoa processing such as fermentation, drying and roasting. However, less research has been conducted to analyse the composition of Peninsular Malaysia cocoa bean at different processing stages. Thus, the purpose of this study was to determine the proximate, phytosterol level, antioxidant content and activity of Peninsular Malaysia unfermented, unroasted, roasted cocoa beans and cocoa shells. Analysis involved was proximate analysis, total phenolic compound (Folin–Ciocalteu reagent assay), antioxidant activity (2,2-diphenyl-1-picrylhydrazyl scavenging assay) and phytosterol composition. Results show that the crude fiber of unroasted cocoa beans and cocoa shells increased from 17.19 to 28.45% and 13.86 to 16.06% respectively after roasting process. The roasting process is suspected to increase the dietary fiber content of cocoa products due to the interaction between polysaccharides, protein, polyphenolic and Maillard products at high temperature. The total phenolic content in cocoa bean and cocoa shells ranged from 2.42 to 10.82 µg GAE/ml. The unfermented cocoa beans contain significantly (p < 0.05) higher antioxidant activity (92.3%) compared to other samples. This study shows that cholesterol, stigmasterol and β-sitosterol were present in roasted cocoa beans and cocoa shells. Hence, the information on the composition of Malaysia unfermented, unroasted, roasted cocoa beans and cocoa shells are needed to enrich the databases composition as a reference for the cocoa industry

Extraction of cocoa proanthocyanidins and their fractionation by sequential centrifugal partition chromatography and gel permeation chromatography

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)Cocoa beans contain secondary metabolites ranging from simple alkaloids to complex polyphenols with most of them believed to possess significant health benefits. The increasing interest in these health effects has prompted the need to develop techniques for their extraction, fractionation, separation, and analysis. This work provides an update on analytical procedures with a focus on establishing a gentle extraction technique. Cocoa beans were finely ground to an average particle size of <100 μm, defatted at 20°C using n-hexane, and extracted three times with 50 % aqueous acetone at 50°C. Determination of the total phenolic content was done using the Folin-Ciocalteu assay, the concentration of individual polyphenols was analyzed by electrospray ionization high performance liquid chromatography-mass spectrometry (ESI-HPLC/MS). Fractions of bioactive compounds were separated by combining sequential centrifugal partition chromatography (SCPC) and gel permeation column chromatography using Sephadex LH-20. For SCPC, a two-phase solvent system consisting of ethyl acetate/n-butanol/water (4:1:5, v/v/v) was successfully applied for the separation of theobromine, caffeine, and representatives of the two main phenolic compound classes flavan-3-ols and flavonols. Gel permeation chromatography on Sephadex LH-20 using a stepwise elution sequence with aqueous acetone has been shown for effectively separating individual flavan-3-ols. Separation was obtained for (-)-epicatechin, proanthocyanidin dimer B2, trimer C1, and tetramer cinnamtannin A2. The purity of alkaloids and phenolic compounds was determined by HPLC analysis and their chemical identity was confirmed by mass spectrometry

Phylogenetic Analysis of a Spontaneous Cocoa Bean Fermentation Metagenome Reveals New Insights into Its Bacterial and Fungal Community Diversity

This is the first report on the phylogenetic analysis of the community diversity of a single spontaneous cocoa bean box fermentation sample through a metagenomic approach involving 454 pyrosequencing. Several sequence-based and composition-based taxonomic profiling tools were used and evaluated to avoid software-dependent results and their outcome was validated by comparison with previously obtained culture-dependent and culture-independent data. Overall, this approach revealed a wider bacterial (mainly γ-Proteobacteria) and fungal diversity than previously found. Further, the use of a combination of different classification methods, in a software-independent way, helped to understand the actual composition of the microbial ecosystem under study. In addition, bacteriophage-related sequences were found. The bacterial diversity depended partially on the methods used, as composition-based methods predicted a wider diversity than sequence-based methods, and as classification methods based solely on phylogenetic marker genes predicted a more restricted diversity compared with methods that took all reads into account. The metagenomic sequencing analysis identified Hanseniaspora uvarum, Hanseniaspora opuntiae, Saccharomyces cerevisiae, Lactobacillus fermentum, and Acetobacter pasteurianus as the prevailing species. Also, the presence of occasional members of the cocoa bean fermentation process was revealed (such as Erwinia tasmaniensis, Lactobacillus brevis, Lactobacillus casei, Lactobacillus rhamnosus, Lactococcus lactis, Leuconostoc mesenteroides, and Oenococcus oeni). Furthermore, the sequence reads associated with viral communities were of a restricted diversity, dominated by Myoviridae and Siphoviridae, and reflecting Lactobacillus as the dominant host. To conclude, an accurate overview of all members of a cocoa bean fermentation process sample was revealed, indicating the superiority of metagenomic sequencing over previously used techniques

EFFECTS OF COWPEA FORTIFICATION, DEHYDRATION METHOD AND STORAGE TIME ON SOME QUALITY CHARACTERISTICS OF MAIZE-BASED TRADITIONAL WEANING FOODS

Fortification of cereal-based traditional foods with legume protein can improve their nutritional value. It is, however, important to find out the extent to which the addition of cowpea affects the desirable quality characteristics of traditional weaning foods prepared from fermented maize and also to assess the effect of dehydration method and storage time on the chemical, physico-chemical and functional properties of the products. A 3 x 2 x 4 factorial experiment with cowpea level, drying method and storage time as the respective variables was done. The traditional weaning food was prepared by steeping maize in water for 24 hours, mixed with cowpea and co-milled into a meal. A 50%-moisture dough was made with the addition of water and fermented for 24 hours. The product was dried using solar drier (40-60 °C for 72 hours) and oven drier (60 °C for 8 hours), and packaged in polypropylene bags prior to the analysis. Proximate analysis, pH, titratable acidity, fat acidity, water absorption and cooked paste viscosity were monitored over six months under tropical ambient conditions (28 °C, RH 85-100%). Cowpea addition caused only minimal changes in the studied indices with the exception of protein content, which increased from 10.54-14.34% and 10.71-14.42% with 20% cowpea level, respectively, for the solar and oven-dried products. Likewise, no major changes in proximate composition were detected during storage. The product pH and fat acidity increased with concomitant decreases in titratable acidity in the stored samples. The pH levels increased from 4.67 – 5.18 and 4.13 - 4.71, respectively, in the solar-dried and oven-dried products within the six months storage period whilst titratable acidity levels decreased slightly during storage of the product. The cowpea level, drying method and storage time showed comparable variations on the cooked paste characteristics measured. The application of cowpea fortification and dehydration to traditional weaning foods is, therefore, a viable option of promoting the nutritional qualities of traditional weaning foods with prolonged shelf life stability. Key Words: Cowpea fortification, dehydration method, storability, traditional weaning foods, chemical and functional properties. Effets de l'enrichissement avec du niébé, la méthode de déshydratation et la durée de conservation sur certaines caractéristiques qualitatives des aliments de sevrage traditionnels à base de maïs Resumé L'enrichissement des aliments traditionnels à base de céréales par adjonction de protéines végétales (légumineuses) est susceptible d'améliorer leur valeur nutritionnelle. Cependant, il est essentiel de connaître l'étendue des effets de l'adjonction du niébé sur les caractéristiques qualitatives souhaitables des aliments traditionnels de sevrage préparés à partir du maïs fermenté. Il est également important d'évaluer l'incidence que la méthode de déshydratation et la durée de conservation ont sur les propriétés chimiques, physico-chimiques et fonctionnelles des produits. Une expérience factorielle 3 x 2 x 4 a été faite avec comme variables respectifs la concentration de niébé, la méthode de déshydratation et la durée de conservation. L'aliment de sevrage traditionnel a été préparé de la manière suivante : on a laissé tremper du maïs dans l'eau pendant 24 heures, ensuite ce maïs a été mélangé aux niébés. Ce mélange a été broyé et réduit en farine. L'adjonction d'eau à cette farine a donné une pâte moelleuse (50% d'humidité) qu'on a laissée fermenter pendant 24 heures. Le produit a été séché en utilisant le séchoir solaire (40-60 °C pendant 72 heures) et dans un four de séchage (60 °C pendant 8 heures), et emballé dans des sachets en polypropylène avant d'être analysé. L'analyse de la composition, le pH, l'acidité titrable, l'acidité grasse, l'absorption de l'eau et la viscosité de la pâte cuite ont été suivis sur une période de six (6) mois dans les conditions tropicales ambiantes (28 °C, RH 85-100%). L'adjonction de niébé n'a pas causé de changements importants dans les indices étudiés, à l'exception de la teneur en protéines. Celle-ci a augmenté car elle est passée de 10,54 à 14,34% et de 10,71 à 14,42% avec une concentration de niébé de 20% respectivement pour les produits soumis au séchage solaire et ceux dont le séchage a été effectué au four. Il en est de même pour la composition globale : aucun changement important n'a été détecté pendant la conservation. Le pH du produit et l'acidité de la matière grasse ont augmenté tandis que le taux d'acidité titrable a diminué dans les échantillons conservés. Les concentrations du pH ont augmenté : elles sont passées de 4,67 à 5,18 et de 4,13 à 4,71 respectivement pour les produits séchés au soleil et ceux séchés au four pendant une période de six mois, tandis que les taux d'acidité titrable ont légèrement diminué pendant la conservation des produits. La concentration de niébé, la méthode de déshydratation et le temps de conservation ont montré des variations comparables sur les caractéristiques de la pâte cuite qui ont été mesurées. L'application de l'enrichissement avec du niébé et la méthode de déshydratation aux aliments de sevrage traditionnels est donc une option viable pour la promotion des qualités nutritionnelles des aliments de sevrage traditionnels conservés pendant une longue période. Mots-clés : enrichissement avec du niébé, méthode de déshydratation, aptitude à la conservation, propriétés chimiques et fonctionnelles, aliments de sevrage traditionnels. AJFAND Vol.4(1) 200