Partial characterization of starch obtained from Ramon (Brosimum alicastrumSwartz), oxidized under different conditions

Extraction, modification, and characterization of native litchi seed (Litchi chinesis Sonn.) starch

BACKGROUND

Litchi seeds, because of their high starch content, have the potential to serve as a valuable non-conventional source of starch with various applications. This study aimed to optimize the extraction of native litchi seed and its modification using citric acid. Response surface methodology was used to determine the optimal combination of the independent variables extraction temperature (30-60 °C), and extraction time (4-20 h), to obtain the maximum starch yield (%). Starch was then modified chemically with citric acid concentrations of 20% and 40% to investigate its effect on physicochemical, morphological, and functional properties.

RESULTS

The second-order polynomial model effectively described the experimental data, demonstrating a satisfactory fit for the observed results. The optimized condition with the highest starch recovery (212.4 g kg-1 ) was found to have an extraction temperature of 30 °C and an extraction time of 11 h. It was observed that an increase in concentration of citric acid resulted in a decrease in amylose content, swelling power, and solubility, and the water absorption capacity of modified starch increased. The scanning electron microscopy (SEM) micrographs showed that citric acid modification resulted in surface irregularities, whereas the shape and size of granules remained unaffected. Not much difference was observed in the X-ray diffraction (XRD) pattern of modified starch except for the decrease in the intensities of peaks. An effect on the thermal properties of modified starch was also observed.

CONCLUSION

The results of the study reveal that extraction temperature and extraction time are critical factors, exerting a significant effect on the extraction yield of starch. Furthermore, modified starches with improved functional properties can serve as novel and versatile sources of starch in various food and non-food sectors. © 2023 Society of Chemical Industry.

Physicochemical, Mechanical, and Structural Properties of Bio-Active Films Based on Biological-Chemical Chitosan, a Novel Ramon (Brosimum alicastrum) Starch, and Quercetin

The properties of biological-chemical chitosan (BCh) films from marine-industrial waste and a non-conventional Ramon starch (RS) (Brosimum alicastrum) were investigated. Blended films of BCh/RS were prepared to a volume ratio of 4:1 and 1:4, named (BChRS-80+q, biological-chemical chitosan 80% v/v and Ramon starch, BChRS-20+q, biological-chemical chitosan 20% v/v and Ramon starch, both with quercetin), Films from commercial chitosan (CCh) and corn starch (CS), alone or blended (CChCS-80+q, commercial chitosan 80% v/v and corn starch, CChCS-20+q commercial chitosan 20% v/v and corn starch, both with quercetin) were also prepared for comparison purposes. Films were investigated for their physicochemical characteristics such as thickness, moisture, swelling, water-vapor permeability, and water solubility. In addition, their mechanical and structural properties were studied using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA) and Scanning Electron Microscopy (SEM) techniques. Antioxidant activity was evaluated as radical scavenging, and antimicrobial effect was also determined. The BCh and RS films presented similar tensile strength values compared with commercial biopolymers. Only films with chitosan presented antioxidant and antimicrobial activity. The FTIR spectra confirmed the interactions between functional groups of the biopolymers. Although, BChRS-80+q and BChRS-20+q films exhibited poor mechanical performance compared to their commercial counterparts, they showed good thermal stability, and improved antioxidant and antimicrobial activity in the presence of quercetin. BChRS-80+q and BChRS-20+q films have promising applications due to their biological activity and mechanical properties, based on a novel material that has been underutilized (Ramon starch) that does not compete with materials for human feeding and may be used as a coating for food products.