Laxmikant S. Badwaik

Antimicrobial and enzymatic antibrowning film used as coating for bamboo shoot quality improvement.

Edible films were prepared with varying proportion of alginate and starch in the ratio of 2:0(F1), 2:1(F2), 1:1(F3), 1:1.5(F4), 1:2(F5), 0:2(F6) with added carboxymethyl cellulose (15%, w/w of starch). The film F5 had superior barrier, mechanical and thermal properties over the other films. Water vapor permeability, moisture absorption, water solubility, breakage strength and elongation capacity of F5 film were reported as 1.21 × 10(-9)g/Pa h m, 9.37%, 40%, 977.3g and 14.62 mm respectively. However, surface characteristics showed the smooth and uniform film and thermal decomposition took place above 200 °C. The film forming solution of selected F5 film, added with antioxidant and antimicrobial extracts was coated on bamboo shoots and stored for 5 days. The film was successful in lowering the browning of bamboo shoots, and also successfully inhibited surface microbial load. Moreover, the moisture loss of coated shoot was less compared to uncoated.

Effect of ultrasound-assisted osmotic dehydration pretreatment on the convective drying of strawberry

The work was planned to produce dietetic dehydrated strawberries with application of ultrasound osmotic dehydration (UOD) as pretreatment. A Box-Behnken design (BBD) were employed to characterize the UOD strawberry process, optimize and investigate the effect of independent variables like ultrasound time (10, 20 and 30min), concentration of osmotic solution (distilled water, 32.5 and 65 °Brix) and temperature (20, 30 and 40°C) on the water loss (WL), solid gain (SG) and weight reduction (WR). The same BBD were used to estimate the main effects of OD without ultrasound treatment. A multi-criteria optimization based on maximal possible values of WL and WR and minimal value of SG was achieved. This was 20.5min of ultrasound time, 47.5 °Brix osmotic solution concentration and 31°C medium temperature. The effects of UOD carried out under the optimized operating conditions on kinetics of convective air drying of strawberry at 40, 50 and 60°C, and velocity of 1m/s, using the phenomenological model of Coupled Washing/Diffusion (CWD). Starting accessibility, moisture effective diffusivity Deff value and activation energy (Ea) were calculated from similar-Ficks law and analogous Arrhenius equation, respectively with and without shrinkage correction. Color difference, Chroma and hue angle of fresh and UOD-air dried strawberries were evaluated. Quality attributes were estimated through the assessment of the phenolic content, antioxidant activity, rehydration capacity, and X-ray powder diffraction characteristics.

Ultrasound treated potato peel and sweet lime pomace based biopolymer film development

Treatment and management of food processing waste is a major challenge for food industry. Potato processing industry generates tremendous amount of peel and consider it as zero valued waste. Again, pomace generated after juice extraction from sweet lime pulp is considered as waste and not properly utilized. Whereas these waste could be utilized for the development of biodegradable packaging film to overcome environmental issues. Composite films were prepared with varying proportion of potato peel powder (PP) and sweet lime pomace (SLP) in the ratio of 0:1(A), 0.5:1(B), 1:1(C), 1:0.5(D), 1:0(E) with an ultrasound treatment of 45min, and 0:1(F), 0.5:1(G), 1:1(H), 1:0.5(I), 1:0(J) with an ultrasound treatment of 60min. Ultrasound was applied for 45 and 60min to film forming solutions to break down biopolymer particles small enough to form a film. All the films were analyzed for their barrier and mechanical properties. It was observed that increasing ultrasound treatment times gives better result in film properties and less PP content also gives better film properties, from these observations film G prepared with 0.5:1 (PP:SLP) showed better characteristics among all other films. Water vapor permeability, moisture absorption, water solubility, breakage strength and elongation capacity of G film were reported as 7.25×10-9g/Pahm, 12.88±0.348%, 38.92±0.702%, 242.01±3.074g and 7.61±0.824mm respectively. However, thermal decomposition for film G took place above 200°C. The film forming solution of selected G film, added with clove essential oil (1.5%) as an antimicrobial agent was wrapped on bread and stored it for 5days. The film was successful in lowering the weight loss, reducing the hardness and inhibition of surface microbial load from bread sample.

Optimization of Microwave Assisted Extraction of Antioxidant Extract from Garcinia pedunculata Robx.

The process of microwave assisted extraction of antioxidants extract from Garcinia pedunculata Robx. was optimized using response surface methodology. A Box-Behnkem design was used to investigate the effects of three independent variables, namely solvent concentration(%), solvent to sample ratio(v/w), and radiation time(min) on total antioxidant activity by DPPH and ABTS radical scavenging activity. Optimal conditions for extraction of antioxidants concluded that the solvent concentration be 70.79%, solvent to sample ratio be 20:1, and irradiation time at 4.73 minutes. However, the antioxidant activity of the extract was found to reach upto 85.98% DPPH radical scavenging activity and 19.23 mg-trolox equivalent/g dry weight. FTIR study revealed that, the extraction of antioxidant extract was higher with increase in irradiation time, but the antioxidant activity of the extract was lower with increase in time. The structural changes in plant material after extractions observed by light microscopy provided visual evidence of the disruption effect.

Effect of ultrasound and centrifugal force on carambola (Averrhoa carambola L.) slices during osmotic dehydration

Osmotic dehydration (OD) of carambola slices were carried out using glucose, sucrose, fructose and glycerol as osmotic agents with 70°Bx solute concentration, 50°C of temperature and for time of 180min. Glycerol and sucrose were selected on the basis of their higher water loss, weight reduction and lowers solid gain. Further the optimization of OD of carambola slices (5mm thick) were carried out under different process conditions of temperature (40-60°C), concentration of sucrose and glycerol (50-70°Bx), time (180min) and fruit to solution ratio (1:10) against various responses viz. water loss, solid gain, texture, rehydration ratio and sensory score according to a composite design. The optimized value for temperature, concentration of sucrose and glycerol has been found to be 50°C, 66°Bx and 66°Bx respectively. Under optimized conditions the effect of ultrasound for 10, 20, 30min and centrifugal force (2800rpm) for 15, 30, 45 and 60min on OD of carambola slices were checked. The controlled samples showed 68.14% water loss and 13.05% solid gain in carambola slices. While, the sample having 30min ultrasonic treatment showed 73.76% water loss and 9.79% solid gain; and the sample treated with centrifugal force for 60min showed 75.65% water loss and 6.76% solid gain. The results showed that with increasing in treatment time the water loss, rehydration ratio were increased and solid gain, texture were decreased.