Search

Cissus quadrangularis is an extensively utilized medicinal plant in India which has numerous health benefits. Hence, the drying kinetics of Cissus was studied using fluidized bed dryer to identify suitable drying conditions and to understand moisture removal and its connection to process variables. The present research aimed to determine a suitable drying model of fluidized bed drying of Cissus quadrangularis Linn., determine the effective moisture diffusivity of the drying process and the activation energy, and investigate the effects of temperatures on the drying kinetics of Cissus. The drying experiments were conducted at three different air temperatures (40, 50 and 60 °C), bed thickness of 5 cm, constant air velocity of 8 m/s and 0.5-1 cm length Cissus samples. The experimental drying data was fit into thirteen thin layer models and the best model describing the drying of Cissus was selected based on the correlation coefficient (R), root mean square error (RMSE), and reduced chi-square (X2). The drying process occurred in a falling rate period for all the drying air temperatures and a constant rate period was not observed. Among all the thirteen models tested, approximation of diffusion was found to explain the thin layer drying behavior of C. quadrangularis accurately. The effective moisture diffusivity for Cissus was in the range of 1.54 - 3.12x 10-10 m²/s and the activation energy was 30.76 kJ/mole, respectively. Hence, fluidized bed drying is more effective for convective drying of Cissus and the drying models are useful for selecting the best operational condition for fluidized bed dryer and design of an equipment. [ABSTRACT FROM AUTHOR]

The present work reports a novel, continuous, specific, and colorimetric coupled method for the assay of phospholipase A2 (PLA2), which involves use of acyl-CoA synthetase (ACS) as coupling enzyme and Dilinoleoyl Phosphatidylcholine (DLPC) as substrate. This method is based on the principle that free fatty acids (FFA) produced by PLA2 are acted upon by ACS, which requires Coenzyme A (CoA) as co-substrate. The PLA2 activity was measured in terms of amount of CoA utilized in the coupled reaction, determined indirectly by measuring unreacted CoA using 5,5'-dithiobis (2-nitrobenzoate). The PLA2 assay was in agreement with Michaelis–Menten equation (Vm = 11.9 nmole. min−1 mg−1, Km = 5.3 nmole, Vm/Km = 2.2 min−1 mg−1). This method provides a true measure of PLA2 in comparison to other available methods, wherein PL analogs were used rather than the natural PL used in our study. The embedded advantages of this method would have wider acceptability and applicability. [ABSTRACT FROM AUTHOR]

An infrared‐assisted hot air dryer was designed and developed for turmeric slices. The dryer has been developed using an infrared heating source, heating coils, and blower. The total power required for the infrared drying and hot air drying was 2.25 kW and 36.35 kWh, respectively, with a blower capacity of 6.06 m3/min. An infrared drying (IRD), hot air drying (HAD), and infrared‐assisted hot air drying (IRHAD) were used to dry turmeric slices (5 mm thickness) at different drying temperatures 50°C, 60°C, and 70°C with constant air velocity 2 m/s and bed thickness 25 mm. The maximum drying efficiency of 25.22% and the minimum specific energy consumption of 1.24 kWh/kg were observed in the IRHAD method at 70°C and considered as the best drying method for drying turmeric slices. The drying rates values were double in IRHAD than IRD and HAD. Seven drying models, namely, Newton, Page, Modified page, Diffusion approximation, Two‐term exponential, Henderson–Pabis, and Logarithmic, were used to validate the experimental data obtained during drying. Based on the maximum R2 value and lowest error values, the Page model was found to be the best fit for characterizing the drying kinetics of turmeric slices. At 60°C drying temperature, the logarithmic model and two‐term exponential model were found best fit for HAD and IRHAD, respectively. Practical Applications: Recently, turmeric gaining a lot of economic importance due to its antiviral properties and health benefits. Turmeric has many applications in the food industry, including natural coloring agents, flavor enhancers, and preservatives. Washing, boiling, drying, polishing, and size reduction are the unit operations involved during the processing of turmeric. The commercial value of turmeric can be decided based on the percentage of volatile compounds present. Many studies observed that the reduction in volatile compounds due to improper drying. The farmers following the sun drying techniques, which consume more time, non‐homogenous drying, and lesser drying rate. Hence, an efficient alternate drying technique should be identified to overcome the problems faced by the farmers and turmeric processing industries. In this context, the present study was undertaken to design an infrared‐assisted dryer for efficient, quick, and uniform heating of turmeric slices. [ABSTRACT FROM AUTHOR]

Abstract Background Volatilomes from natural plants and microbes imparts diverse antifungal properties to suppress the growth of plant pathogens and therefore can be a suitable alternative of chemical fungicides. The present experiment was to study effect of volatiles produced by natural plants and microbes on the fungal growth of Pythium aphanidermatum, which is a tomato seedling pathogen. Results Isolate of P. aphanidermatum, causing damping off in tomato were isolated and incubated at 25 ± 2 °C. The isolate was tested for the anti-oomycetes activities of volatiles in vitro. The volatiles produced by the leaves of Mentha spicata and Cymbopogon citratus showed the maximum inhibitory effect of 45.56 and 24.70 percent, respectively on the mycelial growth of P. aphanidermatum, whereas, the pathogen was not inhibited on exposure to the volatiles of macro-basidiomycetes fungi. The volatiles of T. asperellum showed the maximum inhibitory effect of 69.26 percent against P. aphanidermatum. The study also included the identification of Volatile Organic Compounds (VOCs) involved in the suppression of pathogens by Headspace Gas Chromatography Mass Spectrometry (HS GCMS). The results revealed the production of carvone by the leaves of M. spicata; citronellol and geraniol by C. citratus; isopentyl alcohol and limonene by T. asperellum with increased peak area percentage and these compounds possessed antifungal properties. The vaporous action of isopentyl alcohol completely suppressed the mycelial growth of P. aphanidermatum, which is highly correlated to the T. asperellum extract on pathogenic growth. While the compounds, carvone, and citronellol showed the maximum inhibitory effect of 89.02 and 85.49 percent, respectively when used at 500 ppm and also altered the sporulation behavior of P. aphanidermatum. Conclusion Results showed that volatiles of M. spicata and T. asperellum have anti-oomycetes action on pathogenic growth leading to a distortion of sporulation of P. aphanidermatum. High antifungal properties make VOCs suitable for incorporation as a new integrated plant disease management programs.

Several macrobasidiomycete fungi have potential biological properties naturally to combat fungal diseases. F.oxysporum f.sp. lycopersici is a soil-borne ascomycetous fungus, which causes disease in several vegetable crops. The present study aimed to explore the antifungal activity of VOCs produced by several macrobasidiomycete fungi against F. oxysporum f.sp. lycopersici. The VOCs emitted by macrobasidiomycete fungi were demonstrated by the inverted sealed plate assay against the target pathogen. Among the mushroom isolate tested in vitro, the VOCs exhibited from Coprinus cinereus inhibited 70 % mycelial growth of F. oxysporum f.sp. lycopersici, followed by Ganoderma lucidum (60.28 %) and Lentinus edodes (35.28 %). In addition to inhibition of the pathogen, the headspace volatiles emitted by the effective isolate were trapped by Tenax column and subjected to GC-MS analysis. A total of 15 and 25 VOCs were identified from C. cinereus and G. lucidum, respectively. Among them, Alfa copaene showed a peak area percentage of 7.82 (14.99 RT) in Coprinus cinereus. followed by 2 undecanone. Similarly, trichloromethane and 1- pentanol produced from G. lucidum, showed high relative abundance of 71.5 per cent at 9.84 RT and 70.3 per cent at 2.69 RT, respectively. The VOCs produced by macrobasidiomycete fungi could possess antimicrobial activities against the fungal pathogen. These volatile compounds may be explored as a novel biocontrol agent against soil borne pathogens of vegetable crop. [ABSTRACT FROM AUTHOR]

A total of 9 strains consisting of both V. volvacea (5 cultivated strains viz., CBE TNAU 1401 to 1405; 2 wild strains viz., CBE TNAU 1505 and 1516) and V. bombycina (one cultivated strain CBE TNAU 1406 and one wild strain CBE TNAU 1504) were evaluated to ascertain the variation in their morphological, cultural and molecular characters. Among strains tested, CBE TNAU 1505 was the best strain, which showed earliness in spawn run, more biomass production in unit time and more chlamydospores production with high density. In the trials conducted with partially decomposed paddy straw, the highest yield of 1041.2 g per 5 kg of substrate with an average biological efficiency of 20.8 per cent was recorded with CBE TNAU 1505. Molecular detection of Volvariella strains through 5.8S rDNA regions showed that ITS primers had amplified a product size between 700 and 740 bp. RAPD - PCR phylogenetic analyses revealed 2 major clusters. V. volvacea strains showed approximately 13 per cent genetic similarities with the strains of V. bombycina. [ABSTRACT FROM AUTHOR]

Studies were conducted to extract and evaluate the intracellular bioactive molecules of Ophiocordyceps sinensis against plant pathogens. Methanolic fraction of mycelium borne bioactive molecules at 200 µL concentration showed the maximum mycelial inhibition of Fusarium oxysporum f. sp. cubense (48.67 per cent) and F. o. f. sp. lycopersici (46.47 per cent), which cause wilt disease in banana and tomato, respectively. GC-MS analysis of methanolic fraction of mycelial mat extract indicated the presence of 14 different compounds hydroxylamine; glycerin; oxime-,methoxy-phenyl; adipamide; 1,2,3-Benzenetriol; cyclododecane; imidazole-5-carboxylic acid; 1,3,5-Benzenetriol; 1,3-Cyclohexanedione, 2-propyl; 2-Propenoic acid, tridecyl ester; n-Decanoic acid; 5-Undecene, 9-methyl; L-Ornithine, N5-(aminocarbonyl) and pyrrolo [1,2-a]pyrazine-1,4-dione, hexahydro. Among these, the compound hydroxylamine identified at 1.817 RT exhibited the maximum peak area of 35.00 per cent. This compound is also known to possess important pharmacological and antimicrobial properties. [ABSTRACT FROM AUTHOR]