Properties and emulsifying performance of octenyl succinic anhydride-modified starch from an Andean Pseudocereal: Cañihua (Chenopodium pallidicaulle Aellen)

Abstract

Cañihua (Chenopodium pallidicaulle Aellen) is an underutilized Andean pseudocereal with high starch content. The objective of this study was to evaluate the physicochemical, structural and functional properties of native cañihua starch (CS) esterified with 2-Octen-1-yl succinic anhydride (OSA) at 3 % level (CS-OSA), and to investigate their application in oil in water emulsions (O/W) in comparison to quinoa starch (QS; QS-OSA). The oil/water emulsions stabilized with native and OSA-modified gelatinized starch were evaluated for emulsifying activity (EA), emulsion stability (ES), and storage stability of morphology, particle size distribution, polydispersity index (PDI), volume mean diameter, and visual appearance. The degree of substitution and reaction efficiency were 0.0191 and 82.7 % for CS, 0.0179 and 77.5 % for QS, respectively. FTIR analysis confirmed successful OSA incorporation, revealing new peaks at 1722 cm⁻¹ and 1563 cm⁻¹. The main changes in the functional properties after esterification included increased particle size (CS: 0.942–1.167 µm; QS: 1.085–1.304 µm), and peak viscosity (CS: 4327.5–6886.0 cP; QS: 4903.0-8654.0 cP). Additionally, there was reduction in amylose content (CS: 12.6–10.51 %; QS: 10.12–8.89 %), crystallinity (CS: 26.34–17.87 %; QS: 28.10–25.53 %), syneresis at day 7 (CS: 7.29–0.28 %; QS: 30.16–0.25 %) pasting temperature (CS: 66.03–62.3 °C and QS: 68.23–62.7 °C) and gelatinization enthalpy (CS: 4.89–3.35 J/g; QS: 8.58–4.30 J/g). Emulsions containing gelatinized OSA starch (EBCS-OSA and EBQS-OSA) showing superior EA and ES than emulsions with gelatinized native starch. After 15 days, EBCS-OSA and EBQS-OSA exhibited higher stability than EBCS and EBQS, with lower D_4,3 values and PDI. These findings support the possible application in industrial processes as emulsifiers, offering a novel approach to leveraging Andean crops.