Influence of Temperature and Screw Pressing on the Quality of Cassava Leaf Fractions

In this study, the development of a mild processing method for cassava leaves to remove cyanogenic compounds with minimum nutritional loss is evaluated. Fresh leaves were reduced in size using a mixer at temperatures of 25 (room temperature), 55, 80, and 100 °C for 1 min before screw pressing to separate the juice and press cake fractions. Cyanide content in the fresh leaves was reduced by 60% at 100 °C and by 57% in the juice sample processed at 25 °C. The press cake cyanide content was low (210 ppm) in both the control and the sample that was processed at 55 °C. An increase in the temperature for processing cassava leaves to 100 °C resulted in a loss of 5–13% of the CP and 7–18% of the vitamin C content. The press-cake fraction had high beta-carotene, lutein, and chlorophyll a and b content, and low values were registered for the juice fraction. Processing fresh cassava leaves at 25 and 55 °C resulted in fractions with high beta-carotene and lutein content. The protein quality of press cake was better than that of juice for feed. Short thermal shredding with pressing resulted in minimal loss of nutrients and a significant reduction of cyanide in the leaves.

Comparison of cyanide content in arbila beans (Phaseolus lunatus l) of East Nusa Tenggara using picrate and acid hydrolysis methods

Arbila beans contains cyanogenic compounds in the form of linamarin (cyanoglucosides), acetone cyanohydrin, and free cyanide, all together constitute total cyanide content. The objective of this study was to compare the cyanide content in arbila beans analyzed by picrate and acid hydrolysis methods. Picrate method measures total cyanide only. Cyanide content was identified by using a picrate paper, which turned into yellow. The absorbance was measured by a spectrophotometer at 510 nm. Acid hydrolysis method measures cyanide in arbila beans in the form of linamarin, acetone cyanohydrin, and free cyanide. Linamarin wa hydrolyzed in H3PO4 solution. Estimated cyanide levels was measured by using a colorimetric procedure. Data was analyzed using Independent sample t-test (SPSS v.16). The results showed that, there was no difference in the total level of cyanide in both methods. Total cyanide measured by picrate and acid hydrolysis method was 2705.17 ppm and 2693.29 ppm, respectively. In addition, the three forms of cyanide content were as follows: linamarin 926.22 ppm, cyanohydrin 556.01 ppm, and free cyanide 1211.06 ppm. Based on the results, both methods can be used for total cyanide analysis. To determine the form of cyanide other than total cyanide, it is recommended to use the acid hydrolysis method.

Optimasi Proses Fermentasi Semi Padat Onggok Singkong Menggunakan Metode Response Surface Methodology (RSM)

The application of semi-solid fermentation has been able to increase the potential for using cassava pulp, an underused biomass from starch processing (tapioca), as foodstuffs which are reflected in an increase in protein content up to 7.07% and a decrease in cyanide content to less than 10 mg/kg (8.78 mg/kg). Further process optimization is required if the cassava pulp fermentation process is to be carried out on an industrial scale. This research was aimed to obtain the optimal fermentation process parameters to produce cassava pulp flour with optimal characteristics as foodstuffs. Optimization of the fermentation process was carried out using the Response Surface Methodology (RSM) with the Central Composite Design model. The optimization results using numerical methods show that the optimal characteristics of fermented cassava pulp flour is obtained in the process parameters: starter concentration 1.58-1.65%, ammonium sulphate concentration 1.00%, and fermentation time 75.01-82.53 hours. The optimal process parameters will produce fermented cassava pulp flour with a protein content of 6.40-6.60%, cyanide content of 7.24-7.61 mg/kg, starch content of 58.14-58.37%, dietary fiber content of 15.83-16.65% and an odour score of 4.50-4.53 (maximum score of 5, like very much) which is very potential to be used as foodstuffs.

Study on drying bamboo shoots by Sasaki heat pump drying technology

The study was conducted to investigate the effects of blanching regimes at the salt concentration and drying temperature using Sasaki heat pump drying technology on the quality of dried bamboo shoots to create a product that can be kept color, flavour, and quality. Fresh bamboo shoots were cut into slices with a thickness of 6 mm, boiled in hot saltwater at 100oC at different concentrations (0, 1, 3, 5%) for 15 minutes. Then, they were dried in the temperature setting differences (30, 40, 50oC) by Sasaki dryers and tested for moisture, color, cyanide content, microorganisms, water compensation capacity, and product sensory quality. Fresh bamboo shoots were boiled in hot saltwater at 100oC, 3% salt concentration for 15 minutes, and dried at 40oC by Sasaki drier for the best quality. This treatment mode provides the lowest color variation and the best water compensation compared to other treatment modes. Dried bamboo shoots are bright yellow, uniform color, characteristic odour, toughness with little deformation, low cyanide content, and microbiological content below the threshold of food hygiene and safety.

Effect of Pre-treatment and Processing on Nutritional Composition of Cassava Roots, Millet, and Cowpea Leaves Flours

Cassava roots, millet and cowpea leaves have short storage life thus the need for simple post-harvest handling and storage protocol to ensure prolonged availability to fully contribute toward food and nutrition security, a major challenge within Sub-Saharan Africa. The current study sought to investigate the effect of pre-treatment and processing on cyanide safety and nutrition composition of cassava roots, millet and cowpea leaves flours. The study used three popular cassava varieties grown along the Kenyan coast, cowpea leaves (M66) grown as vegetable and pearl millet. The study used analytical techniques as guided by AOAC standard methods, to determine the nutritional composition of the individual crops while subjecting them to pre-treatment processes (blanching, peeling, washing, drying, and fermentation) and optimizing for maximum nutrient composition. The cyanide content ranged 7.8–9.5, 3.4–5.0, and 2.2–2.8 ppb for raw, untreated, and fermented cassava flours, respectively. The carbohydrates content was in the range of 35–37, 81.73–83.49, and 70.28–71.20% for raw cowpea leaves, cassava roots, and millet, respectively; the carbohydrate content for untreated flours was in the range of 35.68–35.19, 66.07–83.49, and 66.07–68.89% for cowpea leaves, cassava roots, and millet, respectively; the carbohydrate content for the fermented flours was in the range of 29.06–28.01, 79.68–84.36, and 69.08–70.12% for cowpea leaves, cassava roots, and millet, respectively. The protein content was in the range of 25.69–26.01, 1.2–18, and 11.1–13.3% for untreated cowpea, cassava, and millet flours, respectively; fermented flours protein content was in the range of 25.7–29.3, 1.3–2.2, and 8.5–11.1% cowpea, cassava, and millet flours, respectively. Iron and zinc contents were in the range of 4.31–9.04, 1.0–1.3; 7.98–7.89, 1.21–1.25; 6.58–8.23, 0.99–1.22 (mg/100 g dwb) for raw, untreated, and fermented cowpea flours, respectively. Pre-treatment had significant effects (P ≤ 0.05) on cyanide content and nutritional composition of each of the flours. Farmers should be trained to utilize such simple processing techniques.

Cassava Production, Processing and Utilization in South Western Part of Ethiopia

Cassava is a root crop grown and consumed in south western part of Ethiopia. A survey was conducted to assess the production status, processing and utilization of cassava in three zones in South Western part of Ethiopia. A total of 63 farmers from five Cassava producing Districts were randomly selected for interview. A well-structured questionnaire was administered to individual respondent. The survey result showed that most of the farmers on average allocated less than 0.25ha of land for cassava production and none of the respondents were used improved cassava varieties. More than 86% of the farmers sold fresh cassava while others sold after processing. Of the interviewed farmers 98.4% of the respondents had awareness about hydrogen cyanide content of cassava and conducted different removal measures. More than half of the interviewed farmers responded that most of cassava produced in the area was used for home consumption. Less than 40% of them were used for both market and home consumption. Of the total farmers, 53% of the farmers consumed cassava by boiling and frying, while the others consume either by boiling or frying.

Study of Recycling and Treatment Methods Spent Pot Lining (SPL)

In this study, a summary of the processes performed on the SPL for recycling, reduction in toxicity and treatment were examined on an industrial and laboratory scale. In writing this research, an attempt has been made to address the useful processes that have taken place in this field. Spent pot lining or SPL is a type of solid waste that is produced in the aluminum production process. After 3 to 8 years, the cathode blocks become problematic and can no longer be used, and need to be replaced due to adverse effects on cell function. SPL is known to be a hazardous waste to nature due to its fluoride and cyanide content. Research has shown that SPL ingredients have destructive and very dangerous effects on human DNA, which is why they are so important to maintain and recycle.