Optimization of citron peel pectin and glycerol concentration in the production of edible film using response surface methodology

Pectin-based edible film plasticized with glycerol has been developed, and the effect of pectin and glycerol concentration was optimized using response surface methodology for better mechanical properties and transparency. The upper and lower concentration of pectin (3-5 g) and glycerol (15%-25%) concentration ranges were considered in this study based on the preliminary experiment. The responses of the edible film determined were tensile strength, elongation at break and elastic modulus and opacity. The interaction effects of glycerol and pectin concentrations on edible film properties significantly affected the film properties. Tensile strength and opacity were positively affected by pectin concentrations; however, elastic modulus and elongation at break were negatively affected. Glycerol concentration negatively affected the edible film's tensile strength and elastic modulus. The decrease in the opacity of the biofilm was observed as the pectin concentration increased; however, glycerol had not shown a significant influence on opacity. The numerical optimization provided 4 g of pectin, and 20% of glycerol showed a strong and transparent edible film. The TGA curve showed that the maximum weight loss occurred between the temperatures 250-400 °C due to the loss of polysaccharides. From FTIR analysis, observed peaks around 1037 cm-1 represented the C-O-C stretching vibrations of the saccharide found in pectin and glycerol.

Mechanical properties of tef starch based edible films: Development and process optimization

The non-biodegradable synthetic plastic is one of the greatest challenges facing the food packaging business since it seriously harms the environment. To solve this problem, non-biodegradable plastic may be disposed of more affordably and with less harm on the environment by using edible starch-based biodegradable film. Therefore, the present study was focused on the development and optimization of tef starch based edible films based on mechanical properties. In this study response surface methodology was employed by considering 3-5g of tef starch, 0.3-0.5% of agar and 0.3-0.5% of glycerol. The prepared film showed the tensile strength of 17.97-24.25 Mpa, elongation break of 1.21-2.03%, elastic modulus of 17.58-108.69 MPa, puncture force of 2.55-15.02 N, puncture formation of 9.59-14.95 mm. The findings showed that as glycerol concentrations in the film-forming solution increased, the prepared tef starch edible films' tensile strength, elastic modulus, and puncture force declined while their elongation at break and puncture deformation increased. Tef starch edible films' mechanical characteristics, including as tensile strength, elastic modulus, and puncture force, were increased by the increase of agar concentration. The optimized (from 5 gm tef starch, 0.4 g agar and 0.3% glycerol) tef starch edible film exhibited higher tensile strength, elastic modulus, and puncture force while lower elongation at break and puncture deformation. The composite edible film based tef starch with agar exhibited good mechanical properties and can be suggested for application in food industry as food packaging.

Optimization of spray-drying parameter for production of better quality orange fleshed sweet potato (Ipomoea batatas L.) powder: Selected physiochemical, morphological, and structural properties

Orange Fleshed Sweet Potato (OFSP) tuber is a rich source of β-carotene with potential antioxidants and phenolic compounds, nevertheless it is highly perishable root crop. Hence, we considered the optimization of parameters for the preparation of OFSP powder in spray drying technique. This study was designed by the Response Surface Methodology (RSM) with three factors in three levels considered in Central Composite Design (CCD). In case of spray drying process specification, inlet air temperature (IAT) (150 °C-190 °C), flow rate (FR) (10-20 ml/min), and carrier (Maltodextrin) concentration (MDC) (5-15%) were considered and optimized for better quality OFSP powder. As concentration of maltodextrin increased the powder yield, solubility, β-carotene content of OFSP powder increased, while hygroscopicity is decreased. The optimized conditions comprised of an inlet temperature of 172.71 °C, feed flow rate of 20 ml/min, and maltodextrin of 1% concentration. Under this optimized conditions, OFSP powder yield of 48.460%, with the solubility of 26.839%, β-carotene of 25.823 mg/100 g and minimum hygroscopicity of 13.862% was attained. The SEM images of spray-dried OFSP powder produced from the optimized conditions showed hexagonal in shapes, irregular in arrangement and compact. The OFSP powder had lower relative crystallinity (34.7%). In conclusion, the optimized OFSP powder with highest β-carotene and desirable physiochemical properties was produced and it can effectively utilize in the food formulation products.