Native starch is subjected to various forms of modification to improve its structural, mechanical, and thermal properties for wider applications in the food industry. Physical, chemical, and dual modifications have a substantial effect on the gelatinization properties of starch. Consequently, this review explores and compares the different methods of starch modification applicable in the food industry and their effect on the gelatinization properties such as onset temperature (To), peak gelatinization temperature (Tp), end set temperature (Tc), and gelatinization enthalpy (ΔH), studied using differential scanning calorimetry (DSC). Chemical modifications including acetylation and acid hydrolysis decrease the gelatinization temperature of starch whereas cross-linking and oxidation result in increased gelatinization temperatures. Common physical modifications such as heat moisture treatment and annealing also increase the gelatinization temperature. The gelatinization properties of modified starch can be applied for the improvement of food products such as ready-to-eat, easily heated or frozen food, or food products with longer shelf life.

No abstract

No abstract

Cassava cultivation generates three types of lignocellulosic residues such as stems, leaves and peels. As a part of the investigations on their potential for second generation (2G) bioethanol production, the effect of two cellulolytic enzyme cocktails in enhancing fermentable sugar yield from pretreated (hydrothermal and microwave assisted diluted acid treated) residues was studied. Highest release of reducing sugars was observed from cassava peels, followed by stems, during saccharification for 120 h with Cellic, a multicellulolytic enzyme. Cassava leaves were highly recalcitrant to enzymatic hydrolysis and microwave pretreatment was ineffective. Standardization of enzyme levels showed that 500 mg enzyme protein was adequate for saccharification. Further, sequential saccharification of the pretreated residues using another cellulolytic enzyme, Accellerase for 72 h followed by Cellic for 48 h (at half the optimal dose of both the enzymes) was not advantageous in enhancing the fermentable sugar yield. Two stage process in which the pretreated residues were first saccharified with Accellerase, followed by further hydrolysis by Cellic was also inferior to the single enzyme (Cellic) saccharifiaction. Ultrastructural studies on Cellic treated residues using scanning electron microscopy gave evidence for the hydrolysis of starch almost completely, while fragmented sheaths of cellulose were evident in cassava stems and leaves. The study showed that whilst the carbohydrate in cassava peels could be almost totally saccharified to fermentable sugars, the yield from the other two substrates was not optimal. The presence of higher quantities of lignin in the latter two biomasses compared to peels could be attributed to the lower extent of saccharification.

There is an urgent requirement of replacing the environmentally hazardous petroleum‐based plastics with sustainable and efficient starch‐based bioplastics. Development and detailed characterization of the biodegradable bioplastics from plant‐based polysaccharides such as starch is essential to reduce plastic pollution in the environment. In this research, bioplastics were developed from an equivalent blend of starch from two different sources namely rice and potato (1:1, w/w), crosslinked with different concentrations of citric acid (CA). The effect of CA cross‐linking of starch‐based bioplastics was investigated on its physicochemical and functional properties. The X‐ray diffraction (XRD) spectra revealed that the synthesized bioplastics were amorphous in nature with broad diffraction peaks. Further, the peak at 1716 cm−1 in Fourier transform infrared (FTIR) spectra indicated the formation of ester bonds in CA cross‐linked bioplastics. Atomic force microscopy (AFM) revealed the surface roughness of the bioplastics decreased with increasing concentration of CA. Mechanical and thermal properties of bioplastics were characterized using universal testing machine, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA), respectively.