Central Tuber Crops Research Institute

About: Central Tuber Crops Research Institute is a facility organization based out in Thiruvananthapuram, Kerala, India. It is known for research contribution in the topics: Starch & Fermentation. The organization has 475 authors who have published 587 publications receiving 10285 citations.

Optimization of starch isolation process for sweet potato and characterization of the prepared starch

Abstract: The study was conducted to standardize the parameters of centrifugation method of starch isolation for sweet potato to yield better quality starch. The effects of solid-to-solvent ratio in slurry-making, numbers of blending, slurry filtration and starch washings were studied for obtaining maximum yield and purity of starch with desired color and amylose content. The goal of the study was to develop a suitable process for small scale/on-farm processing of sweet potato for preparation of starch. A widely grown pink-skinned cream fleshed cultivar (Kanjangad) was used for the experiments. The studied parameters were slurry making solid-to-solvent ratio (1:2, 1:3 and 1:4), number of blendings (1 and 2 times), number of slurry filtration water washings (2, 3 and 4 times) and starch washings (2, 3 and 4 times). The study showed that the starch yield, purity, color and amylose were influenced by altering the starch isolation procedures. The solid-to-solvent ratio of 1:2 in the starch isolation process yielded the best results. Also, the increase in number of blendings degraded the purity, amylose and color of starch. The optimal process was slurry making at 1:2 solid-to-solvent ratio and once blending, slurry filtration washing for 2 times and starch washing for 2 times. Accordingly, the starch yield, purity, amylose, and L, a and b values were 13.967 ± 1.135%, 80.640 ± 1.139%, 29.220 ± 0.759%, and 57.88 ± 2.982, 0.386 ± 0.204, and 2.68 ± 0.127, respectively. The prepared starch was characterized for chemical composition, water activity, paste clarity, swelling power, water solubility index, pasting property and granule size and morphology. The study suggested that the prepared starch was suitable for food uses.

Detoxification of cassava during fermentation with a mixed culture inoculum

Abstract: The efficacy of a mixed culture inoculum in detoxifying intact cassava tuber and peel pieces was investigated. Fermented cassava tuber and peel pieces had more linamarase activity than the non-fermented control samples and this might have resulted partly from the release of endogenous linamarase from the retted tuber/peel pieces and partly due to the microbial linamarase. Approximately 24–26% of the total cyanide remained in the bound form in the fermented tuber while 67–79% existed as bound cyanide in the non-fermented controls. In cassava peels, only 15–33% of total cyanide remained in bound form after 72 h fermentation while 58–59% cyanide existed in bound form in the parallel non-fermented control peels. Free cyanide which could be easily eliminated through sun-drying was present at higher concentrations in the fermented tuber and peel compared with the non-fermented samples. The study showed that cassava tuber and peel could be extensively detoxified through fermentation with a mixed culture inoculum.

Cassava latex as a source of linamarase for determination of linamarin.

Abstract: A major constraint in the enzymatic assays for determination of linamarin in cassava is the preparation of purified linamarase. Cassava latex, which exhibits high linamarase activity, was tried as an alternate source of the enzyme. Enzyme yield from latex was compared with that from rind and leaf. Preparations from latex had significantly higher linamarase activity (∼300-fold) compared to leaf and rind. The purification of the enzyme was easier since homogenization of large quantities of tissues could be avoided. A 1 g amount of latex could yield enough enzyme for >3000 assays. Keywords: Cassava; latex; linamarase; linamarin determination

Mathematical modeling and thin-layer drying kinetics of bamboo slices on convective tray drying at varying temperature

Abstract: This study investigated the thin-layer drying characteristics of bamboo slices in a convective tray dryer with three different temperatures viz., 55, 65 and 75C and fit the experimental data to four drying models to identify the best fit model and drying temperature. The drying rate curves of slices typically demonstrate a smooth diffusion controlled drying behavior. The drying rate at the beginning of the process was generally lower at 55C, with a marked difference between it and the other temperatures. The difference between MRs increased gradually at the commencement of drying and the time required for reaching equilibrium moisture content decreases with increasing temperature. The average value of coefficient of determination (r2) and RMSE revealed values varied between 0.94–0.99 and 0.014–0.073, respectively. Page and logarithmic models obtained the highest r2 and least RMSE at all temperatures and better reflected the drying mechanism of bamboo slices than exponential model. Rehydration ratio elevated when salt solution used for rehydration and the weight gain was more irrespective of temperature. Superior rehydration was noticed when the slices were dried at 65C, and it was relatively poor at 75C and 55C. Products dried at 65C recorded highest scores for visual appearance and colour at the end of drying. PRACTICAL APPLICATIONS Consumers are inclining towards taking health-promoting products from nontraditional sources. Bamboo shoots are now an important food crop in the international food market. Bamboo shoot being low in fat, high in dietary fiber and rich in mineral content, like an ideal vegetable, has been used traditionally the world over. The market for bamboo shoots is growing steadily, and more and more people are developing a taste for them. Processing while keeping nutrients intact and enhancement of shelf life of the value-added products assume great significance for business potential due to seasonal availability of bamboo shoots. It would demand process standardization for small-scale processing units. Therefore, the use of hot air in controlled cabinet drying through convective air is far more rapid and provides uniformity and hygiene for industrial food drying processes. Therefore, this study deals in detail about dynamics of thin-layer drying kinetics of bamboo slices and its quality evaluation by rehydration and sensory process.

Hydrothermal modifications of tropical tuber starches – Effect of ANN on the physicochemical, rheological and gelatinization characteristics

Abstract: Cassava, sweet potato and arrowroot starches were hydrothermally modified by ANN under different conditions of temperature, moisture and time duration of treatment and the properties are compared. ANN brought about changes in swelling volume, solubility, gelatinization and rheological properties. The three starches behaved differently after the treatment. All the three tuber starches showed decrease in swelling volume after ANN treatment. The solubility decreased for cassava starch, whereas it slightly increased for majority of annealed sweet potato starches and significantly increased for arrowroot starch. For cassava starch, there was a decrease in peak viscosity, but for the other two starches, it increased after ANN. Differential scanning calorimetric studies showed that ANN resulted in a narrowing of DSC patterns for all the starches. The effect of ANN on the dynamic rheological properties was found to depend up on the source of starch. The modification resulted in increased gel hardness, gumminess, adhesiveness and decreased springiness for the starch gels. Tuber starches became less susceptible to enzyme action after ANN.