Synthesis, Characterization and Application of Carboxymethyl Potato Starch Obtained From Waste

Abstract

Waste potato starch (WPS) was obtained from the food industry during slicing, peeling and washing potatoes in the process of producing potato chips. After it was purified with H 2 O 2 and NaOH at the desired temperature, carboxymethyl potato starch (CMPS), with the DS in the range from 0.04 to 1.24, was synthesized in isopropanol (IPA) and NaOH solution by adding monochloroacetic acid (MCA). Considering all the studied conditions, the best results were achieved when IPA was used as solvent at 45 °C for 180 min and at a NaOH/MCA molar ratio of 2.2:1. CMPS-2, obtained under these conditions, reached a viscosity of 14200 mPa. s (for 2% CMPS in water at 1 rpm) for the highest DS. The samples were investigated by determining their DS and by SEM, FTIR, XRD, NMR and thermal analyses. Moreover, the viscosity of the CMPS aqueous solutions was measured. 100% cotton yarns with different numbers (10/1, 20/1 and 30/1 Ne) were sized with CMPS-29, CMPS-27, CMPS-25 and CMPS-22, and then their tensile strength and elongation at break were measured. The tensile strength of the sized samples increased by 87.65%, compared with that sized with WPS. Also, CMPS with DS 0.04 exhibited considerably better sizing properties, compared to WPS.

Synthesis, Characterization, and Investigation of Coating Properties of Carboxymethyl Acorn Starch (CMAS)

“…Signals between 73.33 and 71.12 ppm are associated with resonances from C2, C3, and C5 carbon atoms. [ 11,59–61 ]…”

“…While the resonance at 60.31 ppm is attributed to carbon atom C‐6, the new signal at 63.26 ppm originates from the C‐7 atom incorporated into the structure due to carboxymethylation. [ 11,62,63 ]…”

“…The degree of substitution by the carboxymethyl group was determined by quantifying the number of carboxymethyl groups on CMASs in Table 2 using the previously described method. [ 11 ] Briefly, carboxymethyl acorn starch was moisturized by 1 mL of ethanol, dissolved in 50 mL of distilled water, and added 20 mL of 0.187 M NH 4 Cl buffer and adjusted to neutral pH. The whole mixture was poured into a flask with 50 mL of 0.039 M in copper sulfate salt (CuSO 4 ∙5H 2 O).…”

“…[8][9][10] Carboxymethyl starch (CMS), an ether derivative of starch, is a white to creamcolored, odorless powder. [11] It has received considerable attention in industry and research because of negatively charged functional groups (CH 2 COO − ) in the structure, solubility in cold water, lower gelatinization temperature, changes in rheological profiles, and less retrogradation. [12] Carboxymethylation is a widespread etherification method for starch, which is derived by treating starch with mono-chloroacetic acid (MCA) in a robust alkaline catalyst.…”

Carboxymethyl Starch/Medium Chain Fatty Acid Compositions: Rheological Changes During Storage and Selected Film Properties

“…Thanks to its cold water solubility and presence of carboxymethyl (─COOH or ─COO − Na + ) functional groups it is widely applied in many branches of industry, for example, textile and paper industry, pharmacy, cosmetics, and environment protection. [1,2] Moreover, its aqueous solutions can be used as binders for sand foundry [3][4][5] wood, [6] drilling mud, [7,8] DOI: 10.1002/star.201900240 or production of electrorheological fluids. [9,10] Viscosity of CMS solutions is a very important factor in many applications and it can be regulated by, for example, optimization of starch etherification parameters, [11,12] slight crosslinking [13,14] or additive incorporation, for example clays, into solutions.…”