Lactic acid food fermentation in tropical climates

Journal of Biology, Agriculture and Healthcare, 2019

Effective processing and knowledge of the food composition of indigenous staples are imperative for optimal benefit from the nutritive value of food products. This study investigates the effect of different processing methods on the chemical composition of cassava productsBitter variety of cassava was harvested from a farm in Akpabuyo Local Government Area of Cross River state, Nigeria. The raw bitter cassava roots were peeled and divided into five equal parts of about 500g each. They were processed into garri, "fufu", dry "abacha" wet "abacha", and cassava starch. The "garri" was produced by grating, fermenting (72hrs), sieving and toasting the raw cassava. Cassava starch was produced by fermenting the raw cassava at room temperature (31 o C) in a root water ratio of about 1:3w/v for 5 days. The "Fufu" was prepared by boiling moulded cassava starch in water for 15 min. After which it was pounded. Wet "abacha" was produced by cutting (10cm) and boiling the cassava roots for about 25mins. After which it was sliced into jardinière shape of about 3 x 3 x 18mm batons and soaked for 8 hours. Dry "abacha" was produced by shredding the boiled (25mins) raw cassava and sun drying it for 5 days. The products were dried using a food dehydrator (40 o C) and stored in an airtight container for chemical analysis. The products were analyzed using standard AOAC laboratory methods. Data were analyzed using Statistical Package for the Social Sciences. Mean and standard deviations were calculated and significance accepted at p<0.05.The results of the proximate composition of the products were as follows; moisture (13.2-65.1%), Ash (0.2-0.5%), Fat (0.3-0.9%), Dietary fibre (1.2-4.3%), protein (0.6-1.6%) and available carbohydrate (32.1-81%). The Energy contents of the samples ranged from 688 KJ in dry "fufu" to 1451 KJ in dry "abacha". "Garri" had the highest calcium (20mg/100g), phosphorus (56mg/100g), potassium (222mg/100g) and sodium (7mg/100g) contents. The raw starch had the highest magnesium content of 10mg/100g. The percentage contributions of the products to the recommended nutrient intake (RNI) of adults were as follows: "fufu" had the highest contribution of phosphorus (10%). Sodium (0.1-0.4%), potassium (1-6mg %) and magnesium (1-4%) contributions were generally low in all the products. The Protein (1-3%) and fat (0.5%-1%) contributions to the RNI were low but that of carbohydrate was high and ranged from 30% in "fufu" to 62% in "dry "abacha". "Garri" had the highest contribution of dietary fibre (17%). Dry "abacha" and "garri" had the highest energy contributions of 17% to the RNI of adults. All the cassava products had low levels of hydrogen cyanide which ranged from 3.42mg/100g in "garri" to 7.57mg/100g in "fufu". The traditional processing used for processing raw bitter cassava into dry "abacha" is shown to be insufficient in reducing the HCN to a safe level of <50mg/kg so further processing is recommended. Knowledge of the chemical composition of cassava products will enable consumers to make informed food choices for better nutrition and health outcome.

African Journal of Biochemistry Research, 2010

A major challenge in using cassava peel as feed for animals is the presence of cyanogenic glycosides and the low concentration of protein. The present study investigated the possibility of upgrading cassava peels using fermented cassava pulp juice. Cassava pulp juice was squeezed out of grated cassava pulp and fermented for 3 days at ambient temperature. The microorganisms in the fermented pulp juice were identified as Aspergillus niger, Aspergillus flavus and Lactobacillus spp. Non-sterile cassava peels were sun-dried, milled and inoculated with fermented cassava pulp juice over a 7-day period. Controls were treated with either sterile distilled water, autoclaved inoculum or phosphate buffer (pH 5) over the same period. After 7 days, the cyanogenic glycoside content of the peels, determined by the silver nitrate titration method, had decreased to 12.3% (p < 0.05) of the value for untreated peels while the cyanogenic glycoside content of the controls was 38.8-42.9%. Proximate analysis of 7-day inoculum-treated and untreated cassava peels showed that the protein content of the treated peels had increased 10-fold and significant decreases in starch and fat content were recorded. The fibre content remained unchanged. The present findings show that microorganisms present in fermented cassava pulp juice are capable of enhancing the nutritional value of cassava peels by increasing the protein content and reducing the cyanogenic glycoside content to levels safe for consumption by livestock.

Food Science and Technology, 2013

Cassava starch factories produce residues that can be commercialized as food ingredients. The objective of this study was to evaluate the microbiological safety of cassava peel and bagasse during storage, with and without chemical treatment. The bagasse was acidified with lactic acid, and the peel was immersed in a sodium hypochlorite solution. The microbiological analyses were carried out for 72 h after harvest. All of the samples showed the absence of pathogenic microorganisms, and the acidification and sanitization were effective in controlling total coliforms. Cassava bagasse and peel samples can be considered safe for consumption by humans as ingredients for other food products.

Review on Effect of Processing on Cassava Anti-Nutritional Factors and Impacts on Health Review Article, 2020

Cassava is a valuable source of food for developing countries, Different processing techniques exist to remove cyanogens andt heir effectiveness depends on the processing steps and the sequence utilized, and it often is time-dependent. The proximate composition of raw and boiled cassava tubers was not significantly different (P> 0.05), except in moisture, fat, carbohydrate and Energy value. High levels of the antinutrients in raw cassava tubers (20.56mg/100g Tannins; 1,16mg/100g oxalate and 3.36mg/100g phytate) make them unsafe and unsuitable for human consumption except after processing. Crushing and sun-drying cassava roots made into flour removes 96% to 99% of total cyanogens, whereas soaking and sun-drying into lafun or fufu, or soaking and fermenting and roasting into gari or farina, removes about 98% of cyanogens. For cassava leaves, which have 10 times more cyanogens than roots, pounding and boiling in water is an efficient process to remove about 99% of cyanogens. Other strategies to reduce toxicity include development of low-cyanogen cassava varieties and cassava transgenic lines with accelerated cyanogenesis during processing. Fermentation and oven-drying are efficient processing methods to remove phytate (85.6%) and polyphenols (52%), respectively, fromcassava roots. Sun-drying the leaves, with or without prior steaming or shredding, removes about 60% phytate. Cassava is a nutritionally strategic famine crop for developing countries and, therefore, reducing its toxicity and improving its nutritional value is crucial.

British Journal of Applied Science & Technology, 2016

Aims: This study was aimed as the assessment of dried cassava-fermented chips (DFCC) efficacy in terms of their fermentation acceleration and cyanogens reduction potential. Study Design: An experimental study design was employed in order to achieve the objective of the study. Place and Duration of Study: The study was carried out in the Laboratoire de Microbiologie of the University of Yaoundé 1, Cameroon between October 2011 and August 2014. Methodology: Commercial fermented cassava chips samples were analyzed for their performances to accelerate the retting of cassava roots. The performances of DFCC were determined by periodical measure of the degree of softening of the roots in retting process by penetrometry for 4 days. Further, cassava chips were produced at different fermentation times and Original Research Article Nkoudou et al.; BJAST, 13(3): 1-10, 2016; Article no.BJAST.22262 2 assessed for the same properties. Finally, the best fermentation time to obtain cassava-fermented chips capable to reduce efficiently the retting time was determined and chips produced at this time were used after different pre-treatments in order to assess their impact on the fermentation performances and detoxification of cassava roots as compared to spontaneous retting. Results: Results indicated that DFCC samples collected have high retting performances variability correlated to their fermentation time and microbial concentration. The best DFCC used as cassava retting accelerator (CRA) was obtained after 96h of fermentation (CRA-96). It permitted to reduce the retting time from 71.3±8.5 hours to 35.8±1.4 hours compared to the spontaneous fermentation; and final cyanides contain of 7.86±0.00 ppm corresponding to 98.8% reduction. Optimization assays showed that CRA-96 when soaked for 12 h before use, reduce retting time by 58.5% but did not modify cyanides reduction. Conclusion: The adoption of the CRA-96h as cassava retting accelerator by cassava fermented by-products producers would be great advantage for them who often only ret for 1-2 days and then get into trouble with large cyanide levels in their flour.

New Advances on Fermentation Processes [Working Title]

The cassava plant is grown in tropical and subtropical countries, which represents, alongside with its by-products, an important source of food and feed. Hence, this plant has the capacity to promote the economic development of those countries and provide food security. However, cassava has some disadvantages due to the antinutrient compounds produced in its tissues. In addition, the cassava roots have a low protein content. Due to the economic and practical advantages, the solidstate fermentation (SSF) has been used as a cost-effective and efficient processing method to detoxify the cassava products and enrich them in nutrients. This chapter reviews the solid-state fermentation technique of cassava products for the production of valuable components for food and feed applications, microorganisms involved in this process, and key factors used to optimize the SSF process.

The bioconversion of some agro-wastes resulting from microbial activities in biotechnological relatedness has greatly enhanced the nutritional composition and reduction in its anti-nutritional content for useful end-products formation. In this present study, cassava peels were fermented for 96 h at room temperature 28 ± 2 o C. Seven species of bacterial (Lactobacillus plantarum, Bacillus subtilis, B. megatarum, L. fermentum, L. bulgaricus, L. casei, L. delbrueckii) and five species of fungi (Aspergillus flavus, Mucor mucedo, Penicillium citricum, A. flavus, Rhizopus racemosus) were identified. The pulverized samples were pretreated with lactic acid before pasteurization, and then inoculated with a loopful bacterial isolate prior fermentation. The proximate composition and total cyanide content of the fermented cassava peels were determined. The result of the proximate analysis revealed that there was an increase in the protein content of the natural and pretreated fermented cassava peels from 4.80 to 6.59 and 6.24 to 10.46. There was no considerable difference in the ash content while there was a decrease in fibre content from 16.91 to 11.20 and 13.34 to 10.21. Anti-nutrient such as cyanide decreased in the natural and pretreated fermented sample from 10.0 to 5.59 and 0.02 to 0.01. However, the improvement in the nutritional component and reduction in cyanide content of cassava peels occurred with increase in fermentation time.

Asian Food Science Journal

Sweet and Bitter Cassava tubers were fermented for production of cassava flours. The samples were peeled, washed with potable water and cut into slices of 5-6 cm length. They were steeped separately in water to ferment spontaneously for 4 days. The samples were serially diluted and 0.1 ml aliquot inoculated on appropriate media and incubated for isolation of bacteria and fungi. Physico-chemical, cyanide and proximate status of the fermented samples were determined. Staphylococcus aureus, Lactobacillus spp., Bacillus spp., Klebsiella spp., Corynebacterium spp., Aspergillus niger, Penicillium, Mucor, Rhizopus and Candidia species were isolated. Lactobacillus, Bacillus and Candida species remained till the end of fermentation. Sweet cassava had total viable bacterial counts range: 3.6 x 102 - 4.1 x 105cfu/ml; coliform counts: 2.7 x 102cfu/ml - 3.5 x 105cfu/ml and fungal counts 1.6 x 102cfu/ml - 2.3 x 105cfu/ml while bitter cassava had total viable bacterial counts: 3.3 x 102 - 3.7 x 10...

Drying Technology, 2009

Sweet cassava from the Cook Islands was washed, peeled, and hammer milled. It was spread on metal trays to a thickness of about 2 mm and kept in an enclosed transparent tunnel for 6 h in the sun to encourage endogenous linamarase activity. The end covers were removed and normal solar tunnel drying continued for 2 to 3 days or until quite dry. The temperature of the cassava pulp, the relative humidity in the tunnel, and weight of the cassava pulp were measured at regular intervals. It was found that the temperature of the cassava pulp and relative humidity in the enclosed tunnel rose rapidly to a level that caused the maximum level of linamarase activity. At the end of the 6-h period of fermentation, the total cyanide levels had reduced to well below the 10 ppm on a dry matter basis as recommended by the Codex Alimentarius Commission for food applications of cassava. Solar drying was continued until the moisture content in the product reached a safe level for storage.

International Journal of Biochemistry Research &amp; Review, 2018

Cassava (Manihot esculenta Crantz) is a starchy staple food that previous researches have showed to contain cyanogenic compounds, precursors of hydrocyanic acid, undoubtedly toxic for humans. The aim of this study is to compare the effect of traditional and improved cassava Original Research Article