Structural and physicochemical properties of starches from kernels of loquat fruits
Loquat is widely cultivated in subtropical regions.Current research mainly focuses on the medicinal and edible development of the leaves and fruits.However,as a processing waste,little research has been conducted on the loquat kernel and its main component starch.In this scenario,the loquat kernel starches from two main loquat varieties(Dahongpao and Dawuxing)were extracted to analyze the structure and physicochemical properties.Results showed that the extraction yields of loquat kernel starch were 23.97％and 24.64％(expressed based on fresh weight),respectively.The starch granules showed a certain particle size distribution(D50=10.70 μm,12.00 μm;Span=0.93,1.31)and morphology diversity,with the large granules being spherical or hemispherical with a smooth surface,and the smaller granules being ellipsoidal or polygonal.The degrees of branching(DB)of loquat kernel starch were 2.82％and 2.83％.Furthermore,the amylose of loquat kernel starch had hAm,ⅰ=0.54,0.55,βAm,ⅰ=5.40 × 10 4,5.45 ×10 4,hAm,ⅱ=0.58,0.60,andβAm,ⅱ=18.05 × 10-4,18.85 × 10-4.The kernel starches from two varieties of loquat had amylose content of 17.62％and 18.83％,with no significant difference in chain length distribution.The loquat kernel starch crystal type was CA type,with relative crystallinity of 26.98％and 28.40％.The thickness of semi-crystalline lamellas(dBragg)was 9.236 nm,which was a surface fractal(Ds).The physico-chemical parameters such as oil binding capacity,gelatinization enthalpy(ΔHg)and the springiness of gels were not significantly different between the two starches.However,in comparison to Dawuxing,the starch from Dahongpao had higher solubility,swelling power,and greater gumminess and resilience of gels,while the peak pasting temperature(Tp),peak viscosity,hardness and adhesiveness of gels were lower.In addition,the resistant starch content of natural loquat kernel starch granules was above 94％.This study may provide exper-imental references for the potential applications of loquat kernel starch in starch gel foods and anti-digestive biologically active food ingredi-ents.
万方数据
维普
