Emulsifying and Lipid Adsorptive Properties of Starch Nanocrystals from Solanum Lycocarpum Fruits

The emulsifying properties of a nitric acid-hydrolyzed starch nanocrystal (SNC) from Solanum lycocarpum were examined. The scanning electron microscopy of SNC revealed globular particles measuring 89.4 nm (+/- 20) in average. The values of the water absorption index (1.066 g g(-1)) and oil absorption capacity (1.013 g g(-1)) revealed the amphiphilic character of the SNC. The emulsifying properties using ultrasound and Ultra-Turrax, were, respectively, emulsifying activity: 77.81% (+/- 0.92) and 74.95% (+/- 1.09); emulsion stability: 99.43% (+/- 1.32) and 97.30% (+/- 2.78). The characteristics observed for the droplet obtained using ultrasound and Ultra-Turrax were PDI: 0.04 to 0.35, size: 1.514 mu m and 3.579 mu m, zeta potential: -21.35 (+/- 1.06) and -26.80 (+/- 1.27), respectively. The starch nanocrystals/cholesterol resisted simulated gastric/intestinal digestion (retention 94.8%) and anionic detergent (retention 97%). The inclusion of 1.0 or 2.0% (w/v) of SNC resulted in ice creams with 127.9 (+/- 21.1) and 156.6 N (+/- 19.2) firmness and 142.9 (+/- 17.4) and 171.3 kgfmm (+/- 34.3) consistency, respectively. Similarly, using 1.0 or 2.0% (w/v) of SNC, the amount of extractable lipids from ice creams decreased by 34 and 56% and free cholesterol by 29.5 and 46.5%, respectively. Sensory analysis of the ice cream produced with 2.0% (w/v) SNC revealed 96.1% overall acceptability and average scores above 8 for texture, aroma, flavor, and appearance.