Value addition to agro industrial by-products: Effect of temperature and plasticizer on various properties of pellets developed using extrusion technology

Abstract

Pellets were developed from deoiled rice bran (DOB) and paddy husk (PDH) with plasticizers viz. glycerol (GL) and cashew nut shell liquid (CNSL) at temperatures varied between 80 and 120 °C. Plasticizers and temperature had a significant effect on properties of pellets. Specific mechanical energy of the pellets decreased with the increase in temperature. Color, hardness, pellet durability index (PDI), density (loose/tapped), terminal velocity (Vt), water solubility index (WSI), and water binding capacity (WBC) increased with increase in temperature up to 110 °C. However, expansion ratio (ER), Hausner's ratio (HR), coefficient of friction (COF), angle of repose (AOR), and drag coefficient decreased with increase in temperature up to 110 °C. A1110 (DOB‐75 g, PDH‐75 g, GL‐18 ml) and A2110 (DOB‐75 g, PDH‐75 g, CNSL‐18 ml) had the highest values for color (50.22 and 51.57), hardness (472.52 and 495.56 N), PDI (99 and 99.65%), density (loose/tapped), terminal velocity (3.463 and 3.850 m/s), WSI (20.98 and 19.59%), and WBC (5.19 and 4.01 g/g) and lowest values for ER (1.02 and 1.01), HR (1.11 and 1.08), COF (0.425 and 0.412), AOR (23.749 and 22.314°), and drag coefficient (0.216 and 0.177). SEM analysis evidenced that the intermolecular interactions of A1110 and A2110 pellets were better having smoother surface than other samples. A positive correlation was observed between various properties of the pellets suggesting that functional properties can be predicted from engineering properties of pellets. Practical applications Agro industrial wastes viz. deoiled rice bran and paddy husk due to their vast availability and disposal problems can be used in packaging industries. However, the commercialization is still far behind. Therefore, development of pellets using these agro industrial wastes for the development of value added products like biodegradable planting containers can be a better option. Process conditions and formulation for the development of these pellets are important for maintaining shelf stability and various properties during transportation and handling.

In Vitro Antioxidant Activity Optimization of Nut Shell (Carya illinoinensis) by Extrusion Using Response Surface Methods

“…Condition T11 (106.75 • C, 150 rpm) produced the highest WSI (%) value: 4.47 ± 0.10 versus 3.00 ± 0.14 in the control (non-extruded shell). Consistently, similar results were obtained in agro-industrial by-products extrudates like rice bran and paddy husk, the WSI increased with the increment of temperature up to 110 • C [34]. Extruders will provide high shear, rapid heat transfer, and effective mixing in a short residence time.…”

“…The values of the extrudates samples (L*, C*, h•) may be affected by the destruction of thermosensitive pigments. Jan et al [34,37] observed similar results in agro-industrial wastes, and the authors found that the extruder variables had an effect on the color. Thermal processing of food produces reactions, such as Maillard, caramelization, or hydrolysis, which can affect the color in extruded products.…”

“…The physical and chemical structure of the material will be disturbed and changed during the passage through the extruder barrel, resulting in a large specific area to increase. Jan et al and Zheng and Rehmann support the results with the thermal degradation during the extrusion process (high temperatures), as this could be the reason for the physical and chemical change on the material structure, resulting in an increment of the accessibility of cellulose for enzymatic action [34,35].…”

Extraction, Characterization and Application of Cashew Nut Shell Liquid from Cashew Nut Shells

“…Afterwards, the crucible with the content was removed, cooled in a desiccator and weighed. The percentage ash content (%Ash) was calculated using Equation 6.…”

“…Cashew nut shell, an agro waste from the food processing and agro-based industries, necessitates proper disposal so it does not contribute to sanitation challenges which may result in environmental pollution. Of late, scientists have been exploring the use of agrowastes as a source of raw materials (precursors) in synthesizing a number of benign functional products, value-added chemicals, sustainable energy research areas [5] and into upgraded products [6]. Thus, the cashew tree aside its several phytochemical benefits could offer consumers not only the foodstuffs from industry but also the waste generated through processing could be valorized or processed into other products.…”