Fermented Cassava Research Articles

Natural occurrence of ochratoxin A in some marketed Nigerian foods

A total of one hundred and nine samples of maize (Zea mays) (17), millet (Pennisetum spp) (18), guinea corn (Sorghum) (17), acha (Digitaria exilis stapf) (20),sesame (Sesamum indicum) (19) and fermented cassava (Manihot esculenta) flakes (garri) (18) from markets located in Minna and its environs were analysed for ochratoxin A (OTA) by High Pressure Liquid Chromatography (HPLC). OTA was detected in 98.2% of the samples. The levels found were maize (0–139.2 μg/kg), millet (10.20–46.57 μg/kg), guinea corn (0–29.50 μg/kg), sesame seeds (1.90–15.66 μg/kg), acha (1.38–23.90 μg/kg) and garri (3.28–22.73 μg/kg). Maize had the highest level of OTA with “acha” having the lowest content of the toxin. The OTA levels found in marketed food and feed commodities which were mostly (74.3%) above 5 μg/kg, the European Union standard raise public health concern. The study is the first report of OTA contamination of acha, sesame seed and garri in Nigeria and possibly in Africa.

The Effects of Feeding Dried Fermented Cassava Peel on Milk Production and Composition of Etawah Crossedbred Goat

The Effects of Feeding Dried Fermented Cassava Peel on Milk Production and Composition of Etawah Crossedbred Goat

Quality of fermented cassava flour processed into <em>placali</em>

Fermented cassava flour was obtained from Yace variety. Cassava roots were washed, peeled and ground. After adding cassava inoculums at 8% (m/m), the pulp was allowed to ferment for 72 hours at ambient temperature. The fermented dough was removed, squeezed and oven-dried for 48 hours at 55 °C. The dried product was ground and sieved with a 200 μm mesh sieve. Proximate composition and the ability of fermented flour to be processed into placali appreciated by consumers were evaluated. Moisture, protein, ash, fat, total sugars and cyanide contents were low while starch, total carbohydrate and energy contents were high. Minerals like phosphorus, calcium, magnesium, iron and zinc were available and well-balanced. The sensory evaluation test indicated a significant difference (P<0.05) between the different placali samples in terms of visual appearance, odour, taste, texture and global appreciation. It is a clear indication that reconstitution proportion affects all the hedonic appreciations evaluated. Placali prepared from fermented cassava flour were then highly appreciated when reconstitution proportion (flour to water ratio) was within 1:3.5 and 1:3.Keywords: Proximate composition, cooking time, sensory analysis, reconstituted dough

The Effect of Different Fermentation Techniques on the Nutritional Quality of the Cassava Product (fufu)

The nutritional qualities of fufu produced from traditional, brine and backslopping fermentation techniques were evaluated. The cassava roots were steeped in water (1:4 kg/L) for 96 h for the production of traditional-fermented sample while fermented cassava liquor (10%w/v) was used to initiate fermentation in the backslopping technique. Two-staged method that involved fermentation and grating was employed for the production of brine-fermented sample. The resultant “wet fufu” samples were dried at 65C in a cabinet dryer and mechanically milled into flour. The hydrogen cyanide level, proximate composition, functional properties, mineral contents and the sensory evaluation of the flour samples were assessed. Lactic acid bacteria populations comprised more than 95% of the total viable bacteria and remained prominent through the fermentations, while the number of coliforms and moulds declined as the fermentation progressed. Lactobacillus plantarum, L. buchnerii, L. casei were implicated in the brine fermentation. The hydrogen cyanide observed after fermentation and processing were 15.67 ± 0.63 mg/kg, 13.29 ± 0.68 mg/kg and 12.07 ± 0.32 mg/kg for the traditional, brine and backslopping-fermented samples, respectively. Lowest moisture content (10.61 ± 0.15%) was recorded in backslopping-fermented sample and highest (12.69 ± 0.34%) in traditional-fermented sample. The ash and carbohydrate contents range from 0.76 ± 0.23% to 0.92 ± 0.27% and 82.57 ± 0.56% to 84.03 ± 0.58%, respectively. Higher protein contents were observed in brine (2.25 ± 0.19%) and backslopping (2.32 ± 0.13%) fermentations while the lowest crude fiber content (0.84 ± 0.43%) was obtained in the brine-fermented sample. The results of the functional properties show similar trend. Brine and backslopping fermentation techniques offer lighter “fufu” flours and dough as indicated by the lower swelling index (3.16 ± 0.09 g/g and 2.66 ± 0.18 g/g, respectively) and bulk density (0.65 ± 0.03 g/mL and 0.57 ± 0.03 g/mL, respectively). The traditional-fermented sample had the highest water absorption capacity (4.89 ± 0.06%). Brine fermentation significantly (P < 0.05) increased the Ca (0.235 ± 0.004 mg/kg), Na (0.555 ± 0.055 mg/kg) and K (0.504 ± 0.009 mg/kg) contents of fufu flour than the traditional fermentation which were 0.162 ± 0.003 mg/kg, 0.0097 ± 0.011 mg/kg and 0.151 ± 0.003 mg/kg respective. Sensory scores showed that production of fufu using brine fermentation is more preferred than traditional fermentation. PRACTICAL APPLICATIONS In recent times, attention has been drawn to the enrichment of protein in cassava products by various methods. However, brine and backslopping fermentation techniques of cassava roots are valuable biotechnological approach in achieving this. Because cassava has been recognized as a suitable crop for micronutrient intervention in Africa, its planting and processing into various products like “fufu” flour should be encouraged. Fabrication of cheap local dryer, which can hygienically convert the “fufu wet cake” into flours is strongly recommended and should be made available in the rural areas where larger population of the consumers of this cassava product are located.

The Effect of Adding “Tape Singkong” (Fermented Cassava) Juice on the Characteristics of Fermented Milk

This study aimed to evaluate the effect of adding Tape Singkong juice on the characteristic of fermented milk. In the study 4000 ml of milk was used and divided into 20 cups (200 ml/cup). A completely randomized design that consist of five treatments with four replications was used to analyze the data. The treatment are the giving tape singkong juice as much as 0% (A), 22.5% (B), 5% (C), 7.5% (D) and 10% (E) into the milk that contained 2% of Lactobacillus acidophilus. The variable was observed the characteristic of fermented milk that consist of the moisture, fat, lactose and alcohol content, acidity and bacteria colony count. The result of this research indicated that the addition of tape singkong juice up to 7.5% was significantly decreased the content of moisture, fat and lactose and increased acidity, alcohol content and bacteria colony count.

Serological and pathological assessment of lymphoid organs in chicks fed with graded levels of fermented and unfermented cassava diets

Despite the myriad of investigations in literature on cassava utilization in domestic chickens, its effects on the avian specific humoral immune system still remains elusive. This study investigated the effects of graded levels of fermented (F) and unfermented (UF) cassava diets on the lymphoid organs and its subsequent humoral immunological response in domestic chicks. One hundred day-old Yaffa White cockerels were randomly divided into five groups (A to E) of twenty birds each. The replacement of maize with 0%, 20%, 30%, fermented or unfermented cassava root meal was on a quantitative basis in each group fed for 5 weeks. All other ingredients remained constant. The mean body weight in different cassava treated groups (CTGs) showed no significant difference (P>0.05) compared with the control. The bursa and thymic weights showed both decrease and increase significant difference (P<0.05). There was significant decrease in the IBD antibody titers of CTGs compared with the control at week 5. Macroscopically, mild to moderate enlargement and atrophy of bursa of Fabricius, with petechiation of cortical surfaces of the thymus were observed. Microscopically, lesions such as interfollicular edema, interfollicular fibrosis, follicular atrophy, lymphofollicular hypoplasia, dystrophic epithelium, thickened splenic capsule, splenic lymphoid hypoplasia, thymic lymphoid hypoplasia, diffuse medullary thymic haemorrhages and Myoid cells proliferation were the consistent histopathological changes in all the CTGs. In conclusion, this study demonstrated that cassava inclusion feeds could cause subtle sublethal effects to the lymphoid organs of domestic chickens, and consequently lead to vaccine failure when it is administered for a long period of time. Keywords : Lymphoid organs, fermented and unfermented cassava, serology, pathology

Enhancing the Hygienic Quality of Some Ghanaian Food Products by Gamma Irradiation

The microbiological quality (microbial load and profile) of 6 Ghanaian food products was determined before and after irradiation (0 kGy, 5 kGy, 7.5 kGy, 10 kGy) using standard microbiological methods. The microbial load was estimated by the total viable count (TVC) and moulds and yeasts count (MYC). The range of TVC and MYC of the un-irradiated products were 103 cfu/g - 106 cfu/g and 0 cfu/g - 106 cfu/g respectively. Un-irradiated Banku Mix Powder, Fermented Maize Powder and Cassava Dough Powder had relatively low microbial load (TVC ? 6.1 × 103 cfu/g; MYC ? 4.9 × 102 cfu/g). Un-irradiated Fermented Maize Dough, Kokonte Powder and Cassava Dough had relatively high TVC of >106 cfu/g. Eleven and 3 microbial isolates were detected in the un-irradiated and irradiated products respectively and the most common were Aspergillus niger and Bacillus spp. Irradiation dose of 10 kGy eliminated all microorganisms from the products. Doses of 5 and 7.5 kGy reduced the microbial loads of the products by approximately 1 to 6 log cycles to meet national and international standards. The use of low dose gamma radiation by the local food industry could improve the hygienic quality, extend shelf-life and enhance the competitiveness of the Ghanaian food products in domestic and export markets.

STUDIES OF CYANIDE CONTENT AND MICROORGANISMS INVOLVED IN CASSAVA (MANIHOT ESCULENTA) FERMENTATION

Fresh cassava cortex, peels and leaves were studied for their cyanide content and microorganisms involved in their fermentation process. The total bacteria and fungi count, using the standard plate count, the cyanide content of each of the samples and their pH were evaluated. The results obtained showed that the species of Citrobacter feundii, Providentia, Acetobater and Lactobacillus were the bacteria isolated and identified during the fermentation while Aspergilius. Pencillium, Rhizopus, Candida and Geotrichum species were the fungi identified. The total viable bacteria count increased between 5.96 to 9.6, 6.23 to 9.9 and 5 to 9.85 (log 10cfu/ml) respectively for the cortex, peel and leaves while the total viable fungi count increased also between 6.23 to 9.56, 6.15 to 8.58 and 5.3 to 7.94 (log 10cfu/ml) respectively for the same samples throughout five days of fermentation. It was found that the cyanide content decrease with increase in the days of fermentation with the highest cyanide content of 120CN/g recorded in the peels and the lowest of 93.3CN/g in the cortex. The pH of the three samples also decreased with increase in the days of fermentation. It is apparent from the findings that microorganisms are involved in cassava fermentation and the cyanide content of cassava can be considerably reduced by the process of fermentation.

Cassava solid-state fermentation with a starter culture of Lactobacillus plantarum and Rhyzopus oryzae for cellulase production

A mixture of two microorganisms was used as starter culture, with the aims of producing cellulose from fermented cassava roots. Cellulase yields of 430 IU/g were recorded in solid-state fermentation of cassava starch with mixed culture of Lactobacillus plantarumand Rhyzopus oryzae, isolated from cassava dried chips. High cellulase activity (8.6 IU/ml) per unit volume of enzyme broth and high yields of cellulases were obtained and attributed to the growth of both strains on cellulose fraction of cassava roots. In Solid State Fermentation with Starter mix-culture (SSFS), fermentation retting was completed in two days, and significant softening was noticed. No significant softening was evidence in Solid State Sterile Fermentation (SSSF) and Liquid state fermentation (LSF). Keywords: Cassava, cellulases, Lactobacillus plantarum, Rhyzopus oryzae, solid state fermentation, liquid state fermentation.

Microbiological and physico‐chemical characteristics of fufu analogue from breadfruit (Altocarpus altilis F)

SummaryBreadfruit was processed into a novel form analogous to retted cassava or fufu. The fruits and cassava tubers were each peeled, comminuted and fermented for 5 days. The slurries obtained were dewatered, oven‐dried at 50˚C and then milled to flour. Microbial and physico‐chemical analyses of the flour samples were evaluated. During fermentation, total viable count, lactic acid bacteria count and yeast/mould count of breadfruit increased from 2.9 × 104 to 64 × 105, 24.8 × 105 to 11.9 and 6.7 × 105 to 2.6 × 106, respectively. Corresponding increases were recorded for cassava. The ˚Brix of the steep waters increased steadily while the pH decreased over the fermentation period. Pasting characteristics of breadfruit recorded for unfermented breadfruit starch were higher than those of fermented starch (P &lt; 0.05). Processing of breadfruit into a culturally familiar form analogous to fufu will increase the utilisation of breadfruit, especially in several food deficit countries where fermented cassava products are already accepted as staple foods.

Enrichment Value of Yeast-malate Fermented Cassava Pulp and Cassava Hay as Protein Source Replace Soybean Meal in Concentrate on Rumen Ecology in Crossbred Native Cattle

The objectives of this study was to evaluate the influence supplementation levels of Yeast-Malate Fermented Cassava Pulp (YMFCP) replace soybean meal in concentrate on feed-intake, Average Dairy Gain (ADG), rumen ecology and blood metabolites in crossbred native cattle. Five, two years of female crossbred native cattles weighing at 250±10 kg were randomly assigned according to a 5 x 5 Latin square design. The dietary treatments were as follows: T1 = supplementation of YMFCP replace soybean ratio at 0:100%; T2 = supplementation of YMFCP replace soybean ratio at 25:75%; T3 = supplementation of YMFCP replace soybean ratio at 50:50%; T4 = supplementation of YMFCP replace soybean ratio at 75:25%, T5 = supplementation of YMFCP replace soybean ratio at 100:0%, respectively. The cows were offered the treatment concentrate at 1.0%BW. All cows were fed ad libitum of rice straw with water and a mineral salt block. The results have revealed that rumen fermentation, blood metabolites and average daily gain were significantly different for all treatments. The populations of protozoa and fungal zoospores were significantly different as affected by supplementation levels of Yeast-Malate Fermented Cassava Pulp (YMFCP) replace soybean meal in concentrate. Moreover, supplementation levels of Yeast-Malate Fermented Cassava Pulp (YMFCP) replace soybean meal ratio at 50:50% in concentrate with rice straw as roughage source could highest improved ruminal fermentation efficiency, average daily gain including increase populations of bacteria and fungi zoospores, but decreased protozoal populations in rumen of crossbred native cattle.

Supplementation Levels of Palm Oil in Yeast (Saccharomyces cerevisiae) Culture Fermented Cassava Pulp on Rumen Fermentation and Average Daily Gain in Crossbred Native Cattle

Nine, two-years old of crossbred native cattle were used to examine the effects of supplementation levels of palm oil in yeast culture fermented cassava pulp on rumen fermentation and average daily gain. The cows were randomly allocated in a complete randomized design and three replicates (animals) per treatment. The first group (control) was fed on a yeast fermented cassava pulp without palm oil (YFCP0), The second group was fed yeast fermented cassava pulp + palm oil at 1% (YFCP1)and third groups was fed yeast fermented cassava pulp + palm oil at 2% (YFCP2), respectively. The cows were offered the treatment diets at 2%BW and rice straw was fed ad libitum. The results have revealed that supplementation of dietary treatment on feed intake, ruminal pH, ammonia-nitrogen and blood urea nitrogen concentration were non- significantly different, while Average Daily Gain (ADG) and cost production were significantly different and had highest in cattle receiving YFCP2 than those fed YFCP1, YFCP0 diets (633.1, 614.5 and 511.1 g/day of ADG and 0.92, 0.81, 0.73 US$/kgBW of cost production, respectively). The populations of bacteria and fungal zoospores were significantly different as affected by levels of palm oil supplementation. Especially, supplementation of YFCP2 in cattle had highest increase populations of bacteria and fungi zoospore than those fed YFCP1 and YFCP0 but decreased protozoal populations. Therefore, supplementation levels of palm oil at 2% in Yeast Culture Fermented Cassava Pulp (YFCP1) as supplement diets with rice straw as roughage source could highest improved ruminal fermentation efficiency, average daily gain including increase populations of bacteria and fungi zoospores, but decreased protozoal populations in rumen of crossbred native cattle.

Supplementation of Cassava and Durian Hull Fermented Yeast (Saccharomyces cerevisiae) on Rumen Fermentation and Average Daily Gain in Crossbred Native Cattle

Ten, two-years old of crossbred native cattle weighing about at 250±20 kg were randomly divided into two groups according to receive two groups of supplemental dietary treatments by receiving YFCP1 + YFCP2 (T1) and YFCRR + YFDH (T2). The cows were offered the treatment diets at 2%BW and rice straw was fed ad li bitum. Means were compared using pair t-test. All animals were kept in individual pens and received free access to water. The results have revealed that supplementation of dietary treatment on feed intake was non-significantly different, while average daily gain (ADG) and rumen microorganisms especially bacteria and fungi zoospores were significant different and cattle in heifer fed YFCRR + YFDH (T2) treatments and received YFCP1 + YFCP2 (T1) (646.4 and 533.2 g/d). In addition, the ruminal pH, ammonia-nitrogen and blood urea nitrogen concentration were non-significantly different. Supplementation of T2 could improve population of bacteria and fungal zoospore higher than those fed T1, but decreased populations of Holotrich and Entodiniomorph protozoa in rumen. The results indicate that supplementation of yeast fermented cassava and durian hull as supplement diets with rice straw as roughage source could improve ruminal fermentation efficiency, average daily gain in crossbred native cattle.

The effect of sulfide and ammonia on cassava fermentation for ethanol production in an ethanol–methane coupled system

An ethanol-methane coupled system was proposed to resolve wastewater pollution in cassava ethanol production. The wastewater originated from ethanol distillation is treated with two-stage anaerobic digestion and then recycled for medium preparation for the next batch ethanol fermentation, thus eliminating wastewater discharge and saving fresh water. The constituents of the two-stage anaerobic digestion effluent were complex which influenced the ethanol fermentation performance. This paper aimed to study the effect of two constituents in the effluent, i.e. sulfide and ammonia, on cassava-based ethanol fermentation performance. It was found that sulfide reduced the consumption rate of total sugar by significantly inhibiting the growth of Saccharomyces cerevisiae, but the total consumption amount of total sugar at the end of fermentation was not influenced. S. cerevisiae produced more glycerol and less ethanol at the end of fermentation containing higher concentration of sodium sulfide. Ethanol fermentation performance could be hardly influenced by the sulfide in the two-stage effluent because of the very low concentration. More glycerol was produced while final ethanol concentration was reduced when the level of ammonia in the two-stage effluent was higher.

Antifungal Activity of 2 Lactic Acid Bacteria of the Weissella Genus Isolated from Food

In the present study, a total of 116 lactic acid bacteria (LAB) strains isolated from Mill flour and fermented cassava were screened for their antifungal activity. Three strains among 116 were selected for their strongest inhibitory activity against food molds. These 3 strains were Lactobacillus plantarum VE56, Weissella cibaria FMF4B16, and W. paramesenteroides LC11. The compounds responsible for the antifungal activity were investigated. The strains displayed an inhibitory activity against targeted molds at acidic pH. However, the influence of organic acids was rejected according to the calculated minimal inhibitory concentration (MIC). Antifungal compounds were investigated in the cell-free supernatants and phenyllactic acid (PLA) was detected in different amounts with a maximal concentration for Lb. plantarum VE56 (0.56 mM). Hydroxy fatty acid, such as 2-hydroxy-4-methylpentanoic acid, was also produced and involved in the inhibitory activity of Lb. plantarum VE56 and W. paramesenteroides LC11. Antifungal LAB are known to produce PLA and 3-hydroxy fatty acids and other organic acids with antifungal activity. This short communication focuses on antifungal activity from Weissella genus. The antifungal activity was attributed to antifungal compounds identified such as PLA, 2-hydroxy-4-methylpentanoic acid, and other organic acids. Nevertheless, the concentration produced in the cell-free supernatant was too low to compare to their MIC, suggesting that the inhibitory activity was caused by a synergy of these different compounds. Antifungal LAB are interesting to prevent food spoilage in fermented food and prolong their shelf life. In this way, chemical preservatives could be avoided and replaced by natural preservatives.

Effects of Various Inorganic Nitrogen Sources on the Growth and Biomass Production by &lt;i&gt;Candida utilis&lt;/i&gt; Isolated from Fermenting Cassava Tubers

Candida utilis isolated from fermenting cassava tubers was cultivated in salt media containing sucrose as carbon source and different concentrations of ammonium sulphate, potassium nitrate, sodium nitrate and urea used individually as sole nitrogen sources. The yeast was grown in a 100 ml shaken culture and harvested after a 10-day fermentation period. Variations in media composition significantly (P&le;0.05) affected yeast biomass production. Ammonium sulphate at 0.1% (w/v) concentration resulted in the best biomass production of the isolate. Concentrations above 0.1% (w/v) did not result in correspondingly greater biomass yield. Urea gave better yields at lower concentrations but concentrations above 0.07% (w/v) resulted in lower biomass yield. Sodium nitrate and potassium nitrate were inferior to ammonium sulphate and urea as nitrogen sources for yeast biomass production. A kinetic model based on the variations of these inorganic nitrogen supplementation, level of aeration and subsequent biomass production by the isolate was proposed.Keywords: Candida utilis, Nitrogen supplementation, Biomass, Cassava fermentation, Yeast growth

Oxidation of fermented cassava starch using hydrogen peroxide

The effects of oxidation with hydrogen peroxide (H2O2) on the carbonyl and carboxyl content, pasting, expansion and textural properties of oven-dried fermented cassava starch were investigated. A 23 factorial design with three central points and six axial points was used to investigate the effect of H2O2 concentration, pH and temperature on the oxidation of fermented cassava starch; oven-dried and sun-dried fermented cassava starches were used as controls. The conditions of oxidation that presented the carbonyl and carboxyl contents of starch and specific volume and hardness of biscuits similar to the sun-dried fermented cassava starch were observed at the central point of the experimental design (1.5g/100g H2O2, pH 5.0 and 32.5°C). The sun-drying of the fermented cassava starch increased the carboxyl and carbonyl content, specific volume as well as decreased the biscuit hardness when compared to the oven-dried starch. The oxidation with H2O2 provides a fermented cassava starch with characteristics similar to the sun-dried fermented cassava starch and produces more homogeneous products.

Pemanfaatan Limbah Berserat Dalam Konsentrat Untuk Sapi Jantan Umur Satu Tahun

The utilization of fibrous waste in concentrate for yearling male cattleABSTRACT. A series of experiment had been conducted to improved the quality of rice straw, rice bran and cassava solid waste through biological pretreatment using several species of microbes. Based on the digestibility and the fermentation product, indicated that 30 percent of rice straw, 35 percent of rice bran and 35 percent of cassava solid waste was the optimal ratio for concentrate formulated. The present experiment was carried out by experimental method with Completely Randomized Design, on twelve yearling male cattle of Ongole grade. The treatment tested were 3 physical form of the concentrate : (1) unfermented mesh; (2) fermented mesh and (3) fermented pellet. The variables measured were : energy and protein digestibility, rumen fermentation product, nitrogen balance and daily body weight gain. The digestion and balance trial were carried out by the Total Collection Method. The analysis of covariance shown, that there were significantly effects of the treatment tested whether upon the protein and energy digestibility, the nitrogen balance (P0.01), nitrogen ammonia production and daily body weight gain (P0.05), but there was no significantly effect on the Total Volatile Fatty Acid and the proportion of the individual VFA (P0.05). Based on the all variables measured, it was indicated that fermented pellet was the best concentrate (composed by 30% of fermented rice straw, 35% of fermented rice brand and 35% of fermented cassava solid waste).

Impacts of Vehicle Emissions and Ambient Atmospheric Deposition in Nigeria on the Pb, Cd, and Ni Content of Fermented Cassava Flour Processed by Sun-Drying

ABSTRACT A study of air pollution in Nigeria due to Pb, Cd, and Ni contamination of fermented cassava meant for flour production was carried out by AAS. Fermented cassava samples were purchased from farmers in the study area and one-third of each was oven-dried (OD) while the rest were sun-dried either along roadside (RS-SD) or under ambient atmosphere conditions (AA-SD). Mean concentrations (μg/g) for OD samples in year 2008 were: Pb (0.17 ± 0.04); Cd (0.04 ± 0.01); and Ni (0.27 ± 0.05) while RS-SD samples gave Pb (0.24 ± 0.08), Cd (0.04 ± 0.01), and Ni (0.48 ± 0.17). Mean values (μg/g) in 2009 for OD, AA-SD, and RS-SD, respectively, were Pb (0.03 ± 0.01, 0.05 ± 0.02, 0.15 ± 0.08), Cd (0.18 ± 0.01, 0.04 ± 0.02, 0.05 ± 0.02), and Ni (0.09 ± 0.06, 0.21 ± 0.10, 0.57 ± 0.12). Mean concentrations in sun-dried samples were greater (p < .01), while RS-SD samples were 185% in Pb, 53% in Cd, and 176% in Ni greater (p < .01) than AA-SD samples. With an estimated country-wide annual Pb emissions from petrol and diesel ranging from 616,241 to 968,086 kg, and dust, considered the major source of Cd and Ni, and other extraneous factors including metals adsorbed on pavement surfaces, sun-drying of wet foodstuff on the bare surface of roadside pavements could lead to high levels of Pb, Cd, and Ni in such food compared to drying under factory conditions or oven-drying.

Influência da fermentação na qualidade da farinha de mandioca do grupo d'água

A etapa de fermentação na produção da farinha de mandioca do grupo d'água é responsável pelo desenvolvimento de características químicas e sensoriais peculiares no produto. O objetivo deste estudo foi verificar a influência da etapa de fermentação das raízes de mandioca nos principais parâmetros físico-químicos da farinha, seguido de avaliação sensorial da preferência do consumidor. As análises realizadas foram determinação do teor de umidade, cinzas, proteínas, amido e acidez total titulável. O teste sensorial utilizado foi o de ordenação-preferência dos produtos. De acordo com os resultados obtidos, a etapa de fermentação, responsável pelo aumento da acidez total titulável da farinha de mandioca do grupo d'água, foi o único parâmetro que excedeu o valor limite permitido pela legislação brasileira vigente. Com base no resultado da análise sensorial, houve maior preferência dos consumidores pela farinha de mandioca com maior teor de acidez total (3,44 cmol NaOH kg-1), que corresponde à raiz fermentada por 96 horas.