Impact of Process Conditions on Digestibility of Pea Starch

Figures & data

Figure 1 The flow chart of preparing the PSP product.

Figure 2 Sephadex G-200 chromatogram (490 nm) of starch of PSP product before zymolysis (0 min) (A), at 20 min (B) and 120 min (C) after zymolysis.

Table 1 Thermodynamic properties of pea sample before and after processing

Sample	Δh (J/g)	To (°C)	Tp (°C)	Tc (°C)	RS (%)	SDS (%)
Raw pea sample	3.0 ± 0.2^a	75.8 ± 0.4^b	77.0 ± 0.3^b	81.3 ± 0.6^b	38.9 ± 0.6^a	4.7 ± 0.5^a
PSP sample	4.1 ± 0.2^b	41.6 ± 0.3^a	53.1 ± 0.2^a	64.5 ± 0.5^a	47.7 ± 0.8^b	8.5 ± 0.4^b
Note: The values were expressed as mean ± S.D. of 3 assays. Values with the same lower case superscript letter within a column are not significantly different (p < 0.05) as determined by analysis of variance (ANOVA).

Figure 3 Effect of processing conditions on the digestibility of PSP products. A: cooked at 121°C for 3 h; soaked for 2 h; normal heat dehydrated for 30 min; B: cooked for 3 h with material/water ratio of 1:6; soaked for 3 h; normal heat dehydrated for 30 min; C: cooked at 121°C with material/water ratio of 1:6; soaked for 1 h; normal heat dehydrated for 30 min; D: cooked at 121°C for 3 h with material/water ratio of 1:6, normal heat dehydrated for 30 min; E: cooked at 121°C for 2.5 h with material/water ratio of 1:6; soaked for 1 h; after 30 min normal heat dehydrated, continued to stir-heated till 45 min.

Table 2 Correlation between starch content under different processing conditions

Correlation between	r	p
RDS and SDS	0.433	0.02*
SDS and RS	0.983	0.00**
RS and RDS	0.590	0.01**
RDS: rapid digestible starch; SDS: slow digestible starch; RS: resistant starch. The correlation analysis was done between each two different digestible starch using their contents in the total amount of PSP product; **: significant at the level of p < 0.01; *: significant at the level of p < 0.05.