Volume 4 Number 1 2010

CONTENTS AND ABSTRACTS

Robert H. Glew (USA), John K. G. Kramer, Marta Hernandez (Canada), Andrzej Pastuszyn, Jennifer Ernst (USA), Ngouya Djomdi N. (Cameroun), Dorothy J. VanderJagt (USA) The Amino Acid, Mineral and Fatty Acid Content of Three Species of Human Plant Foods in Cameroun (pp 1-6)

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Original Research Paper: Wild edible plants contribute significantly to the diets of populations in the hot, arid regions of the western Sahel, especially during periods of food scarcity. The following three human plant foods were collected in Cameroun and analyzed for their content of 23 minerals and trace elements, 30fatty acidsand the18amino acids common to proteins:the combined shoots and leaves of Abrus precatorius L, Burnatia enneandra nuts and Cadaba farinosa leaves and stems. Only the leaves of C. farinosa contained significant amounts of the two essential fatty acids: 4.11 g/ 100 g α-linolenic acid and 11.2 g/ 100 g dry weight linoleic acid. B. enneandra nuts and C. farinosa stems contained 16.7 and 8.32% protein, respectively. A. precatorius L. leaves and shoots and C. farinosa leaves contained 7.96 and 14.8% protein, respectively. Compared to a World Health Organization (WHO) standard protein, A. precatorius L. leaves and shoots had the highest essential amino acid scores and C. farinosa stems had the lowest scores. All of the plant proteins scored below the WHO protein standard for lysine. All three plants contained significant amounts of calcium, iron, potassium, sodium, magnesium, manganese and zinc. In conclusion, the amounts of protein and mineral elements in all three plant foods and the amounts of the essential omega-3 and omega-6 fatty acids in the leaves of C. farinosa could contribute significantly to the diets of indigenous populations in sub-Saharan Africa. These data should provide public health officials in the region with information that would be useful in advising local populations about the nutrient value of various spontaneous edible plants that grow in the region.

Fatma B. A. Mohy El-Din, Zahra S. Ahmed, Ahmed R. Abdel Latief, Ahmed T. El-Akel, Salah H. Abou-Raya (Egypt) Effect of Hydrocolloid and Surfactant Agents on the Chemical and Rheological Characteristics of Egyptian Balady Bread Dough (pp 7-11)

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Original Research Paper: There are more than 40 different varieties of bread made in Egypt. However, balady bread is the most popular among these varieties. Replacing 20% of wheat flour with corn flour (recommended by the Egyptian government) to narrow the gap between production and consumption of wheat resulted in a faster rate of bread staling. The effect of tested materials (guar gum GG, carboxymethylcellulose CMC, sodium stearoyl-2-lactylate SSL, a-amylase and dry masa flour DMF) on the chemical composition, rheological properties of balady bread dough were investigated using farinography, extensography, and viscoamylography. The results indicated that dough stability and elasticity, and amylograph peak viscosity have significantly improved when hydrocolloid agents were used. The addition of guar gum improved the rheological properties greater than carboxymethylcellulose and the effect was more pronounced with increasing concentrations.

Esther Gyedu-Akoto, Ibok Oduro, William O. Ellis, Frank M. Amoah, James H. Oldham (Ghana) Utilization of Cashew Gum in the Production of Pineapple Jam and Cashew Apple Juice Drink (pp 12-16)

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Original Research Paper: Cashew tree gum is an exudate polysaccharide produced spontaneously or by deliberately inflicting wounds on the bark of the cashew (Anacardium occidentale L.) tree. Its physico-chemical and rheological properties have been found to be similar to those of gum Arabic which finds industrial applications as a thickening agent, emulsifier or stabilizer. This has led to the assessment of cashew gum as a gelling agent and stabilizer in pineapple jam and cashew juice. The optimum formulations for the production of pineapple jam and cashew juice drink with cashew gum were determined using response surface methodology. Significant regression models which explained the effects of cashew gum on the two products were determined. The coefficients of determination, R² for all the response variables which were 0.7 or higher were used to generate contour and response surface plots. Based on the results, the possible combinations of ingredients for the production of jam with the desired sensory qualities were in the range 0.53-0.70, 0.05 and 0.25-0.42 for pineapple pulp, cashew gum and sugar, respectively. Cashew gum was found to be suitable as a clarifying agent rather than a stabilizer in cashew juice production with the optimum level being 0.3.

Agnieszka Kita, Grażyna Lisińska (Poland) Effects of Package Damage on Quality of Fried Potato Snacks during Storage (pp 17-22)

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Original Research Paper: The aim of this investigation was to assess the effect of the degree of package damage on the shelf life of classic potato chips and chips made of dough (fabricated). The degree of package damage significantly affected the quality of fried potato snacks during storage. The higher the degree of package damage, the more intensively the products absorbed water from the environment. The changes in moisture directly affected chip texture, making it harder. A high, positive correlation (r = 0.89) was observed between the hardness of products and the degree of package damage, as well as with the storage period. Fabricated chips had a significantly harder texture and more profound changes regarding shelf life than traditional potato chips. The degree of package damage also influenced the pace of alterations in the fat fraction of the products stored. The pace of hydrolytic and oxidation changes increased as the degree of package damage and storage time increased. Regardless of the length of storage and the kind of package damage, more advanced changes in the fat fraction were recorded for chips made of dough than for traditional chips. Chips stored in packages with less damage (fewer holes), when subjected to sensory assessment, were granted less than 4 points after 2 months of storage, while those stored in open packages obtained the same number of points after just 1 month.

Mahmood Esna-Ashari, Aghil Mahmoodi Pour (Iran) Ultra Violet Irradiation Enhances Resveratrol Production in Organs and Cell Suspension Cultures of Two Iranian Grape (Vitis vinifera L.) Cultivars (pp 23-26)

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Original Research Paper: Resveratrol (3,5,4'-trihydroxystilbene) is a valuable aromatic compound that prevents cancer and coronary heart diseases in human. In our previous study, this compound was primarily extracted from fruits of 147 Iranian grape cultivars and determined by high performance liquid chromatography (HPLC). Of these cultivars, two of the most desirable ones (‘Rajabi Sefid Shiraz’ and ‘Keshmeshi Ghermez’) were selected for the present study and the amount of resveratrol in their leaves and fruits was measured. The amount of this compound in fruits of both cultivars was more than their leaves and those treated with UV ray (λ = 254 nm) also produced more resveratrol than the controls. Callus and cell suspension cultures of leaves and fruits of these cultivars were established and the production of resveratrol in their cells was determined. Callus was produced from leaf and fruit explants of the two cultivars 4 and 6 weeks after culture, respectively. Cells derived from the callus of both explants established in suspension cultures after three subcultures and produced resveratrol. Cells were exposed to UV 6 days after the third subculture when they entered into an exponential growth stage. The amount of resveratrol produced by UV-treated cells was significantly higher than the organs as well as the controls.

Clément Kouassi Kouassi, Rose Koffi-Nevry, Zinzendorf Yessé Nanga (Côte d’Ivoire), Jaime A. Teixeira da Silva (Japan), Kouadio Yao, Joseph Serge Lathro, Kablan Tano, Guillaume Yao Loukou (Côte d’Ivoire) Assessing the Antibacterial Activity and Phytochemical Screening of Capsicum Varieties from Côte d’Ivoire (pp 27-32)

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Original Research Paper: Besides the use of pepper as a food ingredient, many developing countries use it as in indigenous medicine. This study was undertaken to investigate the antibacterial activities of extractsisolated from Capsicum annum L. and Capsicum frutescens fruits and to identify active compounds responsible for this activity. Three Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus and Bacillus subtilis) and four Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Vibrio cholerae and Salmonella typhimurium) were tested. Phytochemical screening was performed by sample adsorption on silica gels, thin-layer chromatography and compounds were identified using a standard staining procedure. The highest amount of extract and percentage of dry material were from C. frutescens var ‘Attie’ (51 ± 3 mg; 10.26%) with acetone in a direct extraction method while for an exhaustive extraction method, methanol extracted the highest dry mass from C. annuum var ‘Jaune’(1994 ± 35 mg; 39.88%). Extracts tested in vitro against bacterial pathogens showed some antibacterial activities based on inhibition diameters: 10 to 28 mm for Gram⁺ bacteria and 10 to 20 mm for Gram^–. The exception was C. frutescens var ‘Doux’, which showed no activity against E. coli and P. aeruginosa. Phytochemical screening revealed the presence of some active compounds such as alkaloids, tannins, flavonoids, polyphenols, sterols and quinines. The activity and presence of compounds known to be biologically active are a validation for the use of Capsicum as a food ingredient and as a therapeutic element of traditional medicine.

Sawsan El-Faham, Hayam Ibrahim, Roshdy Seoudi (Egypt) Differentiation of Some Fresh Meat Species and Their Corresponding Frozen Minced Products Using Visible / Near-Infrared Reflectance Spectroscopy (pp 33-37)

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Original Research Paper: The authenticity and detection of adulteration of meat and meat-related products are major issues in the food industry. A visible-near infrared spectroscopic method as a rapid and easy tool was used to differentiate between seven fresh meat samples and their corresponding frozen minced products of different species (ostrich, beef, buffalo, goat, mutton, camel and pork). A derivative treatment of reflectance spectra improved the classification of all meat species. All the investigated meat samples showed a nearly similar spectral pattern and absorption bands except for ostrich meat. Freezing treatment caused a pronounced increase in the percentage reflection (R%) of mutton and buffalo meat, a decrease in pork and a slight response in ostrich, goat and camel meat.

A. Mathivanan, D. D. Nambudiri (India) Electrophoretic Identification of Fish Species Used in Surimi (Products) and their Quality Evaluation (pp 38-44)

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Original Research Paper: Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to identify species-specific water soluble proteins and salt soluble proteins bands of raw fillets, surimi, sausage and different combinations (1:1; 3:1; 1:3; and 4:1) of surimi mixtures; sausage mixtures from the two species of fish, threadfin bream (Nemipterus japonicus), and bulls-eye (Priacanthus hamrur). 7.5% SDS was most effective in distinguishing the species-specificity between threadfin bream and bulls-eye of raw fish, surimi, sausage and different combinations of surimi mixtures; sausage mixtures.

Ejikeme Nwachukwu, Ijeoma Onyinyechi Ijeoma (Nigeria) Isolation and Characterization of Lactic Acid Bacteria Associated with the Fermentation of a Cereal-Based Product for the Development of a Starter Culture (pp 45-48)

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Original Research Paper: Isolation and characterization of lactic acid bacteria (LAB) associated with the fermentation of maize for the production of ogi (a traditional weaning food) were evaluated for the development of starter cultures. Changes in pH, titratable acidity and LAB counts were investigated during the cereal based-product fermentation. A decrease in pH was associated with an increase in titratable acidity. The LAB were isolated, characterized and identified using morphological, physiological and biochemical methods with an API 50CHL system. The isolates were Lactobacillus plantarum, Lactobacillus cellobiosus, Lactobacillus pentosus, Leuconostoc mesenteroides and Pediococcus pentosaceus. These isolates were capable of growing on sterilized wet milled maize with L. plantarum having the highest potential as a starter culture. Maize inoculated with a pure culture of L. plantarum showed the highest counts of 6.23 × 10⁷ at 96 hrs of fermentation than the other lactic acid bacteria. There was a significant difference (P > 0.05) between the bacterial counts as well as the pH values obtained during the fermentation of maize by the different LAB.

Solange Aka, Florent K. N’Guessan, Yessé Z. Nanga, Guillaume Y. Loukou (Côte d’Ivoire), André I. Mazabraud (France), Marcellin K. Dje (Côte d’Ivoire) Characterization of Lactobacillus Species Isolated from Mash, Sour Wort and Tchapalo Produced in Côte d’Ivoire (pp 49-54)

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Original Research Paper: A total of 146 Lactobacillus strains isolated in tchapalo processing were characterized by phenotypic methods. Of these strains, 82.88% were heterofermentative strains and 17.12% homofermentative strains. Among the 82 strains identified using multiplex PCR methods, 55 strains were identified including L. fermentum (63.63%), L. brevis (21.82%), L. plantarum (9.1%) and L. hilgardii (5.45%). Api 50 CH identification system tested on twenty Lactobacillus strains allowed also to identify L. coprophilus and L. cellobiosus. L. fermentum was the predominant species which appeared in all samples of mash, sour wort and tchapalo. Thirty-one strains were analyzed for acid production and antimicrobial activities against indicator strains (E. coli ATCC 25922, P. aeruginosa ATCC 27853, B. subtilis ATCC 6633 and S. aureus ATCC 25913). Results showed that the acid production by strains varied within strains of the same species and between species also. Four strains were able to inhibit the growth of most of indicator strains with a broad spectrum. The inhibition diameters were between 8 mm and 21 mm.

Silifat Ajoke Sanni, Clara R. B. Oguntona, E. B. Oguntona, Busie Maziya-Dixon (Nigeria) Chemical Composition, Pasting and Sensory Properties of Iron-Fortified Cassava Gari (pp 55-60)

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Original Research Paper: The need to eradicate nutritional anaemia with a local diet is important for successful intervention at the community level in Nigeria. Enhancing the micronutrient content of commonly consumed staple foods like cassava gari can reduce iron deficiency in Nigeria. This study investigates the extent to which inclusion of iron fortificants (sodium iron EDTA, Fe fumarate and Fe sulphate) could affect proximate and mineral composition, pasting and sensory properties of fortified cassava gari samples. Investment cost of iron fortified cassava gari was also investigated. Gari was fortified with these three fortificants at three concentrations (25, 35 and 45 mg/kg). There were significant differences (P < 0.05) in the proximate and pasting properties of iron-fortified gari samples compared to unfortified samples. Iron content of unfortified gari was 12 mg/kg and this value appreciably increased from 17 to 20 mg/kg, 18 to 25 mg/kg and 21 to 28 mg/kg for NaFeEDTA-, Fe sulphate- and Fe fumarate-fortified gari samples, respectively. There were no significant differences (P > 0.05) in taste, texture and odour of unfortified and fortified samples. In terms of overall acceptability, panellists rated unfortified gari samples higher followed by samples with 45 mg/kg NaFeEDTA. The rate of return on investment for iron fortified gari is 1.36.

Kamau Murigu Patrick Njage (Switzerland/Kenya), John Wangoh (Kenya) Use of the Lactoperoxidase System to Enhance Keeping Quality of Pasteurised Camel Milk (pp 61-63)

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Short Communication: The activity of the lactoperoxidase-thiocyanate-hydrogen peroxide system (LPS) varies between species. However, its effect on keeping quality of pasteurised camel milk has not been studied. We investigated the ability of a combination of LPS and pasteurisation to lower survival of microorganisms in pasteurised camel milk. LPS was activated in camel milk followed by pasteurisation after 0, 4, and 8 hrs of storage. Shelf life, specific growth rate and final microbial count were monitored during storage of the milk at 10 and 20°C. Shelf life was 15, 32, 17 and 17 days for non-activated control and those pasteurised after 0, 4, and 8 hrs of storage of the LPS activated raw camel milk respectively during storage at 10°C. At 20°C, the shelf life was 6, 13, 9 and 7 days for non-activated control and those pasteurised after 0, 4, and 8 hrs of storage of LPS activated raw camel milk, respectively. The number of viable bacteria in untreated samples reached 10⁸ after 45 days compared to 10⁵-10⁷ in treated samples during storage at 10°C. Viable counts were 10⁸ after 15 days in untreated compared to 10⁷-10⁶ in treated samples under storage at 20°C. The mean specific growth rates at 10°C storage temperature were 0.51, 0.2, 0.41 and 0.5 for the non-activated control, activated and pasteurised after 0, 4, and 8 hrs, respectively. At 20°C storage temperature, the mean specific growth rates were 1.46, 0.27, 0.69 and 1 for the inactivated control, activated and pasteurised after 0, 4, and 8 hrs, respectively. The LPS can therefore be used to improve the shelf life of camel milk when activation is done prior to pasteurisation.

Rotimi A. Oderinde, Ibironke A. Ajayi, Abidemi A. Oyedele (Nigeria) Kinetic Studies in the Synthesis of Alkyd Resin Using Crude Azadirachta indica and Soybean Seed Oils as Modifiers (pp 64-67)

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Research Note: Medium oil alkyds of 50% oil length, modified with crude neem and soybean seed oils were synthesized using the alcoholysis method with phthalic anhydride and glycerol. Lead oxide (II) and xylene were used as catalyst and azeotropic solvent, respectively. The kinetics of the reaction was monitored by the determination of the acid value of aliquots of the reaction mixtures at 30-min intervals. The initial rate of reaction followed the second order kinetics and thereafter deviations were observed. It was observed that the initial rate of decrease in acid value was more rapid for the soybean medium alkyd than for the neem medium oil alkyd. The second order rate constant for soybean medium oil alkyd was 11.3 × 10^-4g (mg KOH)^-1 min^-1 and that of the neem seed was 2.0 ×10^-4g (mg KOH)^-1 min^-1 . The gel time for the neem medium oil alkyd was found to be two and a half times slower than that of soybean medium oil alkyd; thus giving preference for the synthesis of the soybean medium oil alkyd over that of neem medium oil alkyd.

Rotimi A. Oderinde, Adewale Adewuyi, Ibironke Adetolu Ajayi (Nigeria) Preliminary Toxicological Evaluation and Effect of the Seed Oil of Hura crepitans and Blighia unijugata bak on the Lipid Profile of Rats (pp 68-71)

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Research Note: A preliminary investigation of the possible toxicity effect of the seed oil of Hura crepitans and Blighia unijugata Bak. was carried out on histopathology, some haematological and biochemical parameters of albino rats. The rats were divided into six  groups of five rats each (A, B, C and D were fed with 5% of the test oils, E served as control without oil and F was fed with 5% of known edible oil) and fed for 12 weeks. The phytochemical screening of these oils reveals the presence of glycosides, steroids and flavonoids. The highest body weight gain was found in the group fed with oil from B. unijugata. There was a general difference in the weight of the kidney of all the test groups when compared with that of the control. No death or clinical sign of toxicity was observed in any of the groups. The study shows varying degree of vascular stress characterized by congestive lesions and also the possibility of cellular lipotoxicity based on the alteration of the lipid profile.

Chitra Rajagopal, K. Rajamani (India) Nutritional and Microbial Quality Evaluation of Herbal Drinking Water (pp 72-74)

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Research Note: About 80% of all illnesses in developing countries are related to water e.g., cholera, dysentery, diarrhea, etc. Herbal traditions throughout the world have used infusions and decoctions of herbs in drinking water. This study assessed the antibacterial activity, quality and consumer acceptability of drinking water on treatment with Piper longum and Caesalpinia sappan extracts. Among the various concentrations, 0.5 g P. longum root extract and 0.5 g C. sappan bark extract treated with drinking water recorded high quality, high antibacterial activity and better consumer acceptability.