American Journal of Food Science and Technology

The effect of microbial fermentation on the anti-nutrient composition of some cassava products was evaluated by the inoculation of the pulps of four local varieties of cassava, using microorganisms (Saccharomyces cerevisae and Lactobacillus bulgaricus). The results of the study revealed that microbial fermentation caused significant reductions (P < 0.05) in the cyanide (86%), tannins (73%), oxalate (61%), phytate (72%) and saponins (92%) contents of the cassava products. The results of the study suggest that cassava products can be nutritionally improved with Saccharomyces cerevisiae and Lactobacillus bulgaricus fermentations.

American Journal of Food Science and Technology. 2015, 3(3), 89-96. DOI: 10.12691/ajfst-3-3-6
Pub. Date: July 20, 2015

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Effects of Pre-treatments and Drying Methods on Chemical Composition, Microbial and Sensory Quality of Orange-Fleshed Sweet Potato Flour and Porridge

by Fana Haile, Shimelis Admassu and Abrehet Fisseha

Original Research

This study was aimed to evaluate the effect of pre-treatments and drying methods on the chemical composition (proximate composition, β-carotene content and phytochemicals), functional properties, microbial and sensory of orange-fleshed sweet potato flour and porridge. Physical (blanching) and chemical (1% salt, 0.5% citric acid solution soaked for 20 min) of the sliced OFSP followed by drying (sun, solar and fluidized bed dried) with complete randomized design for chemical composition, functional properties, and microbial load analysis and randomized complete block design was used for sensory analysis. The moisture (4 - 8%), protein (4 - 8%), fat (0.9 - 2.5), ash (4 - 8%), fiber (3.5 - 7%), total carbohydrates (80 - 84%) measured as a function of treatment and drying. The energy contribution of OFSP was determined by difference of the proximate excluding the fiber (352.9-365.6kcal/100g). The salt treated and FB dried had significantly lowest moisture content and highest ash content, citric acid treated and FB dried had significantly highest protein content and gross energy, control and FB dried had significantly highest fiber content, control and sun dried had significantly highest fat content and blanched and FB dried had significantly highest total carbohydrates. The β-carotene (82 -127μg/g), tannin (74 -108mg/100g) and phytate content (51 - 98mg/100g) was measured. Blanched and FB dried was observed better in retention of β-carotene and reduction of phytochemicals (tannin and phytate). The salt treated and FB dried was measured increment with WAC, viscosity and lowest LGC, blanched and FB had highest OAC and high bulk density in the control. The microbial analysis showed OFSP porridge within microbiological acceptable limit. The sensory acceptability showed OFSP was accepted in all sensory attributes. In conclusion, the blanching and FB drying techniques were the best approach in retaining the nutrients.

American Journal of Food Science and Technology. 2015, 3(3), 82-88. DOI: 10.12691/ajfst-3-3-5
Pub. Date: July 16, 2015

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Constraints and Compliances of Traceability in Low Grown Orthodox Black Tea Manufacturing Process

by ChandanaVindika Kumara Lokunarangodage, Indira Wickramasinghe and Kamburawala Kankanamge Don Somathilaka Ranaweera

Original Research

Traceability practices and their compliances in low grown orthodox black tea manufacturing process were examined, while proposing possible solutions for identified major drawbacks. The physical traceability in supply chain was considered one step forward and one step backward from the point of manufacturing, starting from auction/buyer back to supplier. Randomized stratified sampling was used. The traceability was evaluated using a checklist, end product sampling, open ended interviews, observations and internal document studies. The orthodox process was more complicated unlike other production processes due to the different separation techniques employed for grading and variety of grades produced because the sifting/grading was the key to number of different tea varieties. Major traceability issues were observed in leaf collection and grading operations due to complexity of separation through Myddleton, Chota, Michie and Winnower, which reduced the specific amounts produced, where bulking and blending process further extended complexity, while increasing the mixing of different made tea together with increased number of suppliers. Considering 1^st, 2^nd, 3^rd dhool and big bulk with given separation techniques during grading; a single tea leaf could pass many paths before it end up in a specific product due to weight, size and shape of the leaf of a shoot based on the way it was rolled in orthodox rollers, where traceability up to tea bush, grading, blending and traceability of sample back to supplier was not fully complying. Nevertheless, supplier records, traceability after packing, traceability at dispatch and after dispatch were in full compliance, and other factors had varying degree of traceability compliances which make the compliances unachievable. Alternatively, if made tea is considered as bulk material, use of emerging technologies like Radio Frequency Identification (RFID) tags or/and DNA barcoding may be potential tools in rectifying such drawbacks and further research is needed to assess their efficacy in the field.

American Journal of Food Science and Technology. 2015, 3(3), 74-81. DOI: 10.12691/ajfst-3-3-4
Pub. Date: July 12, 2015

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Combining Different Types of Prebiotic Plant Isolates Toward, Enhancing the Growth of Probiotic Organisms

by Fathima Hajara Aslam, Jagath Wansapala and Manel Perera

Original Research

The growth stimulatory effect produced by combining different sources of prebiotics i.e; Fiber isolates from Musa sp pseudostem, polyphenol extracts from Sesbania grandiflora flower petal and non-digestible polysaccharide extracts from Artocarpus heterophyllus seed were assessed against probiotic organisms, Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis BB-12 in vitro in liquid cultures. Different combinations were formulated by integrating the three sources of prebiotics at two different levels i.e; fibre (0.2% and 2%), polyphenol extracts (0.2% and 0.6%) and non-digestible polysaccharide extracts (0.2% and 1.2%) to obtain eight treatments. The formulation which consisted 2% fibre, 0.2% polyphenol and 0.2% non-digestible polysaccharide was able to promote significant biomass increment in Lactobacillus acidophilus, while the treatment consisting 2% fibre, 0.6% polyphenol and 0.2% non-digestible polysaccharide demonstrated highest proliferation for Bifidobacterium animalis subsp. lactis BB-12 in vitro which were statistically different (p<0.05) than other formulations.

American Journal of Food Science and Technology. 2015, 3(3), 67-73. DOI: 10.12691/ajfst-3-3-3
Pub. Date: June 23, 2015

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Effect of Honey and Sugar Solution on the Shelf Life and Quality of Dried Banana (Musa paradisiaca) Slices

by Md. Sultan Mahomud, Md. Keramot Ali, Md. Mostafijur Rahman, Md. Hafijur Rahman, Tajnuba Sharmin and Md. Jiaur Rahman

Original Research

The main purpose of the study was to investigate the effect of solution on the shelf life and quality of banana slices and development of high quality dehydrated banana products. Ripe banana collected from local market cut into 3, 5 and 7 mm slices. Solution effect was assessed using honey, sugar and mixed (honey plus sugar, 1:1) solution. The osmosis samples were dried in a mechanical drier at 65°C for 24 hour up to moisture content 14.6%. Fresh and dehydrated banana were analyzed for their chemical composition. The effect of pre-treatment (4 min steam blanching plus 20 min sulphyting) and nutrient content also evaluate. Percent solid gain was assumed as indicator of solution of solution effect. Percent solid gain slightly decreased (per unit weight) with increasing thickness of banana slices at constant immersion time (3 hour) and concentration (72% TSS). This gain was higher in honey solution followed by sugar solution. The response of taste panel revealed that banana slices prepared by 4 min steaming plus 20 min sulphyting (0.5% KMS) and subsequently dipping in honey solution gave better colour and flavor. It has been also revealed that pre-treatment by 4 min steaming plus 20 min sulphyting (0.3% KMS) and subsequently dripping in honey was gave better colour and flavour of banana slices. So these pre-treated dehydrated products showed highest degree of acceptability. Studies on the effect of various packaging materials showed that the single layer polythene plus keep in tin can gave the best result for storing the dried banana slices. Among the different storage condition of dried banana slices (75% RH, 80%RH and 90% RH), the 75% RH was found most effective for storing the processed slices. However, in all packaging systems and storage conditions, the slices absorbed moisture over the storage period and lost its quality. To maintain better quality of slices for longer shelf-life, the low relative humidity and moisture proof packaging system (polythene plus kept in tin can or laminated aluminum foil) may be required.

American Journal of Food Science and Technology. 2015, 3(3), 60-66. DOI: 10.12691/ajfst-3-3-2
Pub. Date: June 19, 2015

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A Rapid Sample Preparation Method for the Determination of Cadmium and Lead in Spinach and Artichoke Leaves Using Ozone

by Ignacio Machado, María Verónica Cesio, Isabel Dol and Mariela Pistón

Original Research

A novel method for sample preparation using an ozone-based process was optimized for the determination of Cd and Pb using electrothermal atomic absorption spectrometry (ET-AAS). Advanced oxidation processes, which involve the in situ generation of highly potent chemical oxidants, are a promising technology to accelerate the oxidation at room temperature and the degradation of organic matter. A certified reference material of spinach leaves was used to evaluate the methodology. The sample was treated with diluted nitric acid, then a glass device was immersed in the solution and ozone was passed through for 10 minutes. The experimental conditions were optimized by means of a multivariate experiment. Figures of merit were: detection limits (3s): 0.002 mg kg^-1 (Cd), 0.01 mg kg^-1 (Pb), relative standard deviation lower than 10 % for both elements (n=5), the mean recovery was 97.6 % (Cd) and 98.3 % (Pb) compared with the certified value (n=5). The method was also applied for monitoring these elements in artichoke leaves and the results were in good agreement with those obtained with microwave digestion procedure. This procedure is simple, fast and showed to be adequate for the monitoring of these inorganic contaminants in spinach leaves and artichoke leaves.

American Journal of Food Science and Technology. 2015, 3(3), 55-59. DOI: 10.12691/ajfst-3-3-1
Pub. Date: June 14, 2015

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