Navin Chandra Shahi

Optimization of Freeze-Drying Process Parameters for Qualitative Evaluation of Button Mushroom (Agaricus bisporus) Using Response Surface Methodology

Button mushroom cubes of constant cross-sectional area (0.75 cm × 1.5 cm) and varying thickness (2 mm, 5 mm, and 8 mm) were freeze-dried. Pressure (0.04, 0.07, and 0.10 mbar), primary drying temperature (−2°C, −5°C, and −8°C), and secondary drying temperature (25°C, 28°C, and 31°C) were taken as drying parameters. The protein, ascorbic acid, and antioxidant contents were taken as quality estimates for freeze-dried mushrooms. It was observed that the secondary drying temperature affected the protein () and antioxidant content () significantly, whereas all three freeze-drying parameters affected the ascorbic acid content with higher effect due to temperature parameters () as compared to pressure (). The optimized values for protein, ascorbic acid, and antioxidant content obtained using response surface methodology were mg/g, mg/100 g, and mg/g, respectively, as compared to mg/g, mg/100 g, and mg/g, respectively, for fresh button mushrooms. The optimum values for process variables were obtained as 0.09 mbar, 0.36 cm, and −7.53°C and 25.03°C for pressure, sample thickness, and primary and secondary drying temperatures, respectively.

Novel Eco-Friendly Techniques for Extraction of Food Based Lipophilic Compounds from Biological Materials

Plant-based lipophilic compounds such as edible oils, phytochemicals, flavors, fragrances and colours are valuable products in the food, pharmaceutical and chemical industry. Extraction is one of the key processing steps in recovering and purifying lipophilic ingredients contained in plant- based materials. Lipophilic compounds are found in the cells of oil bearing plant seeds. Solvent extraction is the most common commercially used extraction method for low oil content materials. Solvent extraction has more extractability than existing commercial methods, but it also passes serious limitations and environmental issues. The Environmental Protection Agency has been much concerned regarding safety and environmental emissions associated with hexane usage in the solvent extraction process. Bio-solvents resulting from renewable raw materials and in particular from the biomass may become a solution of the existing problem. But the existing conventional extraction methods cannot respond to such solvent and hence need for new novel “Green” extraction technology having potential to overcome all limitations of existing technologies. This review will discuss the various possible novel eco-friendly extraction methods, their scientific concepts, principles, challenges, limitations and technological effort needed for successful implementation at the production scale.

Cracking Force Analysis for Apricot Pit Decortication Based on Mathematical Model of Hertz’s Theory

In decortication of wild apricot pit a mathematical model based on Hertz’s theory of contact stress was developed for the prediction of force required to break the pit. Using pits subjected to a uniaxial compression stress, in their lateral axis between rigid parallel plates, and those propelled to impinge a rigid cylindrical seat along its lateral axis, experimental verification of the model was conducted comparing the theoretical predictions with estimates from the representations of conventional methods employed in pit cracking. Properties including size, shape, and mass, required in the derived model were determined for wild apricot pits. Material stiffness was obtained from the force-deformation curve. Material stiffness obtained was 51.1 × 106 to 46.9 × 106 Nm-1 for different sizes of the pits (12, 11, 10, and <10 mm). The respective ranges of geometric mean diameters were between 16.92–15.05 mm. There was no significant variation of pit sphericity with size of pits. Force prediction from the Hertzian model proposed gave good prediction of cracking force that was not significantly different from that obtained from an impact force decorticator (1.2 kg weight reciprocating with 100 rpm and 30 cm stroke length) and compression force required calculated from a texture analyzer.

Application and comparison of genetic and mathematical optimizers for freeze-drying of mushrooms

Abstract The suitability of genetic algorithm as an optimization tool for freeze drying of mushroom has been explored. The optimized solution set obtained from genetic algorithm was compared to a derivative based goal attainment algorithm (fgoalattain) to identify the better optimizer. Regression models for quality parameters of freeze dried button mushrooms were developed and models with ≥ 85% correlation were selected and compiled into an objective function for optimization. Verified optimal solutions revealed that genetic algorithm was more proficient in optimizing physical quality parameters (rehydration and shrinkage ratio) as contrary to fgoalattain which optimized nutritional characteristics (ascorbic acid and protein) better. The ability of genetic algorithm for optimization from the perspective of a consumer was found to be better.

Effect of Active Packaging and Coating Materials on Quality Parameters of Jaggery Cubes

Jaggery is one of the ancient sweetening agents known to man and is an integral part of the rural diet in many countries. It’s storage is highly influenced due to presence of invert sugars and mineral salt which are hygroscopic in nature. To extend the shelf life of this commodity there is a need of new technologies. Edible coating and active packaging appears one of the good alternatives for this. Edible coating is used as a barrier to minimize water loss while active packaging maintains dry conditions within packages. The independent variables decided for active packaging of jaggery cubes were, moisture absorber (2.64, 4,6,8 and 9.36g), concentration of CMC and HPMC (0.528, 0.8, 1.2, 1.6 and 1.872g/ml) and thickness of high density polyethylene bags (66, 100, 150,200 and 234μm) were taken for research work. The storage study of active packaged edible coated jaggery cubes was conducted for 180 days. The responses via pH, water activity, and reducing sugar were analyzed at different interval. The statistical analysis of each sample was done to check the significance of data. The water activity and reducing sugar decreased with increase moisture absorber, concentration of CMC and HPMC and thickness of HDPE bags. The pH of stored active packaged edible coated jaggery varied from 5.47 to 5.74 and water activity was in range of 0.531 to 0.699 and reducing sugar varied from 1.33 to 2.98 μg/ml. For best shelf life of jaggery. Optimum values of independent variables obtained by compromise optimization of the responses were; 8g moisture absorber, 1.178 g/ml concentration CMC and HPMC and 197μm thickness of HDPE bags for 180days storage.

Application of genetic algorithm in modelling and optimization of cellulase production

The aim of this work was to study the application of genetic algorithm (GA) in modelling and optimization of cellulose production by Trichoderma reesei from pea hull. Enzyme activity of cellulase was determined using Filter Paper Activity (FPA) assay. Optimization of process parameters was performed using mathematical (MO) and genetic optimizers to obtain combination of variables for highest possible enzyme activity. GA generated a higher value of cellulase activity (0.353 U/mL) as compared to MO (0.302 U/mL). The values of independent variables in set (GA, MO) were: agitation speed (127, 120 rpm), %H2O2 concentration (10.36, 5.0), cultivation time (112, 91 h). The investigation highlights that GA could be used as a potential optimizer for processes involving waste utilization.

A comparative study on the quality of laboratory-made and market samples of milkcake-a traditional Indian sweet

A study was conducted to evaluate the quality of milkcake available in market and to compare it with laboratory-made milkcake. Samples of milkcake were collected from commercial manufacturers and analyzed for sensory attributes, chemical characteristics and microbiological quality. Results of the study indicated that various samples collected from the local market of Karnal, were found to vary widely in physico-chemical, microbiological and sensory quality, however, overall quality of laboratory-made milkcake showed less standard deviation as compared to that of samples collected from market. Quality characteristics of market samples were found inferior to the laboratory sample in all aspects of quality parameters, thereby indicating adoption of non-standard procedures and uncontrolled and unhygienic conditions of manufacture, handling and storage at the commercial shops. Hence, standard procedure for the preparation of milkcake be devised and strict guidelines for the manufacture, processing and handling conditions must be formulated and they should be stringently executed both in unorganized and organized sectors effectively.