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.

Biodegradation of cassava starch factory residue using a combination of cellulases, xylanases and hemicellulases.

Abstract: Cassava starch factory residue (CSFR), a low cost solid byproduct of the cassava starch industry, having around 60% unextracted starch and 15% cellulose is a potential candidate for bioethanol production. As the economic feasibility depends on complete degradation of the polysaccharides to fermentable glucose, the comparative hydrolytic potential of four enzymes such as Multifect ® XL, Optimash™ XL, Optimash™ BG and Accellerase™1000 was studied. Whilst the former three enzymes exerted maximum activity at pH 5.0 and 60 °C, Accellerase had optimum activity at pH 4.5 and 60 °C. The enzyme cocktail, Multifect XL-Optimash XL-Accellerase (5, 15 and 20 g enzyme protein kg −1 CSFR respectively) was more effective than sequential process with the same enzyme loading. Hydrothermal treatment (HT) of CSFR for 30 min at 100 °C enhanced the susceptibility to enzymatic cleavage as compared to HT for 45 and 60 min as well as autoclaving or microwave exposure. Optimash BG was the most effective on HT CSFR and approximately 704.8 g glucose was released kg −1 CSFR. The high yield of glucose indicates the potential use of hydrothermally treated CSFR as a cheap substrate for ethanol production.

Proximate composition and sensory evaluation of anthocyanin-rich purple sweet potato (Ipomoea batatas L.) wine

Abstract: Purple sweet potato (PSP) is a special type of sweet potato having high anthocyanin pigment in the root. The starch contents of PSP (root/water homogenised in 1:1 ratio) were enzymatically saccharified [using commercial thermostable enzymes Termamyl® (0.2%) and Dextrozyme®GA (1%)] to fermentable sugars, and the filtrate was ameliorated with cane sugar to achieve 20° Brix, for subsequent fermentation into a red wine using 2% yeast (Saccharomyces cerevisiae) as starter culture. The wine had the following proximate compositions: total soluble sugar (TSS), 2.25° Brix; starch, 0.15 g per 100 mL; total sugar, 1.35 g per 100 mL; TA, 1.34 g tartaric acid per 100 mL; phenol, 0.36 g (caffeic acid equivalent) per 100 mL; anthocyanin, 55.09 mg per 100 mL; tannin, 0.64 mg per 100 mL; lactic acid, 1.14 mg per 100 mL; ethanol, 9.33%(v/v); and pH, 3.61. 2, 2‐Diphenyl‐1‐picrylhydrazyl (DPPH) scavenging activity of the wine was 58.95% at a dose of 250 I¼g mL−1. Principal component analysis reduced the eleven original analytical and proximate variables (TSS, starch, total sugar, TA, phenol, anthocyanin, tannin, lactic acid, ethanol, pH, DPPH) to four independent components, which accounted for 76.65% variations. Sensory evaluation was carried out by sixteen trained panellists on various attributes such as clarity, colour, viscosity, odour, flavour, spritz and finish. Independent ‘t’ test confirmed that all the sensory attributes of the PSP wine scored closely (within 10% variation) to that of a commercial grape wine. The red wine produced contains essential antioxidants and acceptable sensory qualities.

Isolation and identification of antimicrobial secondary metabolites from Bacillus cereus associated with a rhabditid entomopathogenic nematode

Abstract: The cell-free culture filtrate of Bacillus cereus associated with an entomopathogenic nematode, Rhabditis (Oscheius) sp., exhibited strong antimicrobial activity. The ethyl acetate extract of the bacterial culture filtrate was purified by silica gel column chromatography to obtain six bioactive compounds. The structure and absolute stereochemistry of these compounds were determined based on extensive spectroscopic analyses (LCMS, FABMS, 1H NMR, 13C NMR, 1H −1H COSY, 1H −13C HMBC) and Marfey’s method. The compounds were identified as cyclo(D-Pro-D-Leu), cyclo(L-Pro-D-Met), cyclo (L-Pro-D-Phe), cyclo (L-Pro-L-Val), 3,5-dihydroxy-4-ethyl-trans-stilbene, and 3,5-dihydroxy-4-isopropylstilbene, respectively. Compounds recorded antibacterial activity against all four tested bacteria strains of Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. 3,5-dihydroxy-4-isopropylstilbene recorded activity only against Gram-positive bacteria while cyclo(L-Pro-L-Val) recorded no antibacterial activity. Best antibacterial activity was recorded by 3,5-dihydroxy-4-ethyl-trans-stilbene (4 μg/ml) against Escherichia coli. The six compounds recorded significant antifungal activities against five fungal strains tested (Aspergillus flavus, Candida albicans, Fusarium oxysporum, Rhizoctonia solani and Penicillium expansum) and they were more effective than bavistin, the standard fungicide. The activity of cyclo(D-Pro-D-Leu), cyclo(L-Pro-D-Met), 3,5-dihydroxy-4-ethyl-trans-stilbene, and 3,5-dihydroxy-4-isopropylstilbene against Candida albicans was better than amphotericin B. To the best of our knowledge, this is the first report of antifungal activity of the bioactive compounds against the plant pathogenic fungi Fusarium oxysporum, Rhizoctonia solani, and Penicillium expansum. We conclude that the Bacillus cereus strain associated with entomopathogenic nematode is a promising source of natural bioactive secondary metabolites which may receive great benefit as potential sources of new drugs in the agricultural and pharmacological industry.

Inactivation of trypsin inhibitors in sweet potato and taro tubers during processing.

Abstract: In order to understand the extent of elimination of trypsininhibitors during processing of sweet potato (Ipomoea batatas) andtaro (Colocasia esculenta) tubers, a detailed study was conductedusing tubers processed by oven drying, cooking, and microwavebaking Between 80 and 90% trypsin inhibitor (TI) activity wasretained in sweet potato chips up to 2h at 70 °C Among thefour cultivars of sweet potatoes, RS-III-2 trypsin inhibitors were more heatlabile Heating at 100 °C led to rapid inactivation of TI of sweetpotatoes Varietal differences in thermal stability were more pronouncedfor the trypsin inhibitors of taro than sweet potatoes Taro inhibitors werealso more rapidly inactivated than sweet potato TI Between 17 and31% TI activity was retained in cooked tuber pieces of sweet potatoes,while only 3–10% were retained in taro cultivars Very effectiveinactivation of trypsin inhibitors of sweet potatoes and taro could beobtained through microwave baking Flour prepared from taro was devoidof TI activity, while 5–12% TI activity was retained in the flour preparedfrom sweet potatoes The study clearly established that among the fourtechniques used, microwave baking and flour preparation were the best methods to eliminate TI from sweet potatoes and taro