M. Sivarajan

Antimicrobial and antioxidant effects of spice extracts on the shelf life extension of raw chicken meat

The antimicrobial and antioxidant effects of different spice extracts in raw chicken meat during storage for 15 days at 4 °C were studied. Raw chicken meat was treated with BHT (positive control), Syzygium aromaticum (SA), Cinnmomum cassia (CC), Origanum vulgare (OV), and Brassica nigra (BN) extracts and the different combinations as well as the results were compared to raw chicken meat without any additive (negative control). The antioxidant and antimicrobial activities of spice extracts were determined. Total phenolic contents and flavonoid contents were ranged from 14.09 ± 0.78 to 24.65 ± 0.83 mg of GAE/g and 7.07 ± 0.15 to 12.13 ± 0.24 mg of quercetin/g, respectively. The pH, instrumental color (CIE L*, a*, b*), total viable counts (TVC), Lactic Acid Bacteria (LAB) counts, Enterobacteriaceae counts, Pseudomonas spp. counts and 2-thiobarbituric acid reactive substances (TBARS) were determined at a gap of 3 days interval for a period of 15 days. The bacterial counts of T-W-SA+T-W-CC+T-W-OV samples were lower than control samples during storage. T-W-SA+T-W-CC+T-W-OV samples maintained significantly (P<0.05) higher L*, a* and b* values while storing. The TBARS values of T-W-SA+T-W-CC+T-W-OV samples were lowest among the samples. These results show that spice extracts are very effective against microbial growth, lipid oxidation and has potential as a natural antioxidant in raw chicken meats.

Preparation and characterization of mucilage polysaccharide for biomedical applications

In the present investigation, the polysaccharide/mucilage from waste of Abelmoscus esculentus by modification in hot extraction using two different solvents (Acetone, Methanol) were extracted, characterized and further compared with seaweed polysaccharide for their potential applications. The percentage yield, emulsifying capacity and swelling index of this mucilage were determined. The macro algae and okra waste, gave high % yield (22.2% and 8.6% respectively) and good emulsifying capacity (EC%=52.38% and 54.76% respectively) with acetone, compared to methanol (11.3% and 0.28%; EC%=50%) (PH=7) while swelling index was greater with methanol than acetone extracts respectively. The infrared (I.R.) spectrum of the samples was recorded to investigate the chemical structure of mucilage. Thermal analysis of the mucilage was done with TGA (Thermal Gravimetric Analyzer) and DSC (Differential Scanning Calorimeter) which showed both okra and algal polysaccharide were thermostable hydrogels.

Microbial desalination cell for enhanced biodegradation of waste engine oil using a novel bacterial strain Bacillus subtilis moh3

Microbial desalination cell (MDC) is a bioelectrochemical system developed recently from microbial fuel cells (MFCs), for producing green energy from organic wastes along with desalination of saltwater. MDC is proved to be a better performer than MFC in terms of power output and chemical oxygen demand removal, with desalination as an additional feature. This study investigates the application potential of MDC for integrated biodegradation of waste engine oil. This study showed, for the first time, that waste engine oil could be used as an organic substrate in MDC, achieving biodegradation of engine oil along with considerable desalination and power production. Utilization of these wastes in MDC can protect the environment from waste engine oil contamination. Indigenous oil-degrading bacteria were isolated and identified from engine oil contaminated sludge. Degradation of waste engine oil by these novel isolates was studied in batch cultures and optimized the growth conditions. The same cultures when used in MDC, gave enhanced biodegradation (70.1±0.5% ) along with desalination (68.3±0.6% ) and power production (3.1±0.3 mW/m2). Fourier transform-infrared spectroscopy and gas chromatography-mass spectrometry analyses were performed to characterize the degradation metabolites in the anolyte of MDC which clearly indicated the biodegradation of long chain, branched and cyclic hydrocarbons present in waste engine oil.

Production and characterization of cellulose reinforced starch (CRT) films

Starch from Tamarind seed is considered to be a nonedible and inexpensive component, with many industrial applications. Extraction and characterization of tamarind seed starch was carried out for the synthesis of biopolymer. Tamarind seeds were collected, cleaned and further roasted, decorticated, and pulverized to get starch powder. Total starch content present in each tamarind seed is estimated to be around 65-70%. About 84.68% purified starch can be recovered from the tamarind seed. Defatted Tamarind seed starch has an amylose content of 27.55 wt.% and 72.45 wt.% of amylopectin. Morphological (SEM) and X-ray diffraction were used to evaluate crystallinity. Likewise, TGA and DSC of starch have also been analyzed. Thermal properties of starch obtained from tamarind seeds showed good thermal stability when compared to other starch sources such as Mesquite seed and Mango kernel. This study proved that the tamarind seed starch can be used as a potential biopolymer material. Thermo-stable biofilms were produced through initial optimization studies. Predictive response surface quadratic models were constructed for prediction and optimization of biofilm mechanical properties. Correlation coefficient values were calculated to me more than 0.90 for mechanical responses which implies the fitness of constructed model with experimental data.

Integrated Approach to the Problems of Dye Wastewater by Sonolysis and Biological Treatment

The degradation of a reactive dye by combined sonolysis (40 kHz) and biodegradation was studied using Acid red (AR 66) as a model dye. The combined action of ultrasound and biodegradation using Bacillus subtilis was characterized as a function of dye concentration, pH and temperature. Under optimum conditions, AR 66 could be completely degraded within 10 h. The COD analysis was performed and was found that about 90-95% COD reduction was achieved by this hybrid technique. The biodegradation data for AR 66 were fitted to Bridge- Haldane equation with good correlation.

Potential application of corn starch edible films with spice essential oils for the shelf life extension of red meat.

To investigate the effect of corn starch (CS) edible films with spice oils on the stability of raw beef during refrigerated storage.

Bio protection and preservation of raw beef meat using pungent aromatic plant substances

BACKGROUND This study examined the effectiveness of three individual spice (clove, cinnamon and oregano) extracts and their combinations in raw beef meat during refrigerated storage. Meat samples were monitored for microbiological (total viable count, Enterobacteriaceae, lactic acid bacteria, Brochothrix thermosphacta and Pseudomonas spp.) and physicochemical (pH, colour and thiobarbituric acid-reactive substances (TBARS)) attributes. RESULTS Samples treated with the combination of all three spice extracts showed lower bacterial counts and better L*, a* and b* values among treated samples during the storage period. Positive and negative control samples had the highest TBARS values at the end of the storage period. With the addition of spice extracts, TBARS values in raw beef samples were retarded effectively (P < 0.05) compared with control samples, especially when the combination of all three spice extracts was used. CONCLUSION The results of this study show that spice extracts were effective in inhibiting the growth of microbial populations and retarding lipid oxidation during refrigerated storage (4 °C) of raw beef meat. They also suggest that combinations of these extracts may have potential as natural preservatives in raw meat products.

Influence of mechanical disintegration on the microbial growth of aerobic sludge biomass: A comparative study of ultrasonic and shear gap homogenizers by oxygen uptake measurements

Wastewater treatment plant incorporates physical, chemical and biological processes to treat and remove the contaminants. The main drawback of conventional activated sludge process is the huge production of excess sludge, which is an unavoidable byproduct. The treatment and disposal of excess sludge costs about 60% of the total operating cost. The ideal way to reduce excess sludge production during wastewater treatment is by preventing biomass formation within the aerobic treatment train rather than post treatment of the generated sludge. In the present investigation two different mechanical devices namely, Ultrasonic and Shear Gap homogenizers have been employed to disintegrate the aerobic biomass. This study is intended to restrict the multiplication of microbial biomass and at the same time degrade the organics present in wastewater by increasing the oxidative capacity of microorganisms. The disintegrability on biomass was determined by biochemical methods. Degree of inactivation provides the information on inability of microorganisms to consume oxygen upon disruption. The soluble COD quantifies the extent of release of intra cellular compounds. The participation of disintegrated microorganism in wastewater treatment process was carried out in two identical respirometeric reactors. The results show that Ultrasonic homogenizer is very effective in the disruption of microorganisms leading to a maximum microbial growth reduction of 27%. On the other hand, Shear gap homogenizer does not favor the sludge growth reduction rather it facilitates the growth. This study also shows that for better microbial growth reduction, floc size reduction alone is not sufficient but also microbial disruption is essential.

Effects of polyphenols from Caralluma fimbriata on acrylamide formation and lipid oxidation—An integrated approach of nutritional quality and degradation of fried food

ABSTRACT The objective of this study was to investigate the utilization of Caralluma fimbriata an edible succulent cactus as natural antioxidants for retarding acrylamide formation, lipid oxidation, and the degradation of bioactive compounds in French fries due to frying at 190°C. The fresh Caralluma fimbriata extract exhibited the highest phenolic content of 96.4 ± 0.1 mg gallic acid equivalent/g when the raw potato extract showed significantly 27.4 ± 0.3 mg GAE/g before frying. The Caralluma fimbriata extract had the higher flavonoid content of 54.4 ± 0.1 mg of Quercetin equivalent/g, while the raw potato had 38.8 ± 0.2 mg of Quercetin equivalent/g. The total flavonols and flavanols in Caralluma fimbriata were significantly high, and those were found to be 27.6 ±0.8 mg Quercetin Equivalent/g and 19.1 ±0.6 mg Catechin equivalent/g, respectively, and, eventually, higher than potato extract. These bioactive compounds are easily degraded due to frying at high temperatures. The Caralluma fimbriata extract retards the formation of acrylamide precursors in potato, primary and secondary oxidation products, and the degradation of polyphenols after the immersion treatment. The Caralluma fimbriata extract was found to be more effective against acrylamide level (42.5 μg/kg) in French fries. The Caralluma fimbriata treated sample exhibited comparatively better oxidative stability during holding time with highest overall acceptability than the sample treated with butylated hydroxyanisole, distilled water (control) and raw potato (without treatment). The results will provide scientific basis in the use of Caralluma fimbriata as natural antioxidant against acrylamide formation and the oxidative deterioration of bioactive compounds.

Modeling the Kinetics of Antioxidant Extraction from Origanum vulgare and Brassica nigra

In the present research work, the effect of solvents, particle size, solvent/solid ratio, and temperature on the extraction efficiency of oregano (Origanum vulgare) and mustard (Brassica nigra) were investigated. The extraction process proceeded at a fast rate followed by a slower one. Particle size, solvent type, solvent/solid ratio and temperature had a positive effect on the extraction process, and maximum extraction was achieved by ethanol. Extraction kinetics was determined with a mathematical model derived from Ficks second law. The results were verified with Ficks diffusion model for extraction kinetics in all experiments, which provided the initial rate and extent of solid–liquid extraction. Antioxidant values were determined using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2′-azino-Bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The extracts of O. vulgare and B. nigra prepared using ethanol showed optimal antioxidant activity.