In vitro Digestibility of Starch from Ready-to-Eat Cassava and Corn Flours

Slowly digestible starch (SDS) and resistant starch (RS) associate with health benefits when present in the diet. This study aimed to evaluate ready-to-eat corn and cassava flours regarding their commercial presentation (dry or flaked), composition and in vitro digestibility of starch. Sixteen samples from Southern Brazil were procured in the market: eight dry cassava flours, six biju-type (flaked) corn flours and two biju-type cassava flours. Dry cassava flours had higher L* and lower b* values, and higher RS, relative crystallinity and viscosity peak values. Dry cassava flour partially preserves granular starch, as its processing involves lower drying temperatures and lower moisture of the pressed pulp. Dry cassava flours that had higher b* values also had higher rapidly digestible starch (RDS) levels, since higher temperatures are required in their production. Both biju-type flours showed the highest RDS values and no RS due to processing with elevated temperature and high moisture of the pressed pulp. In this study starch digestibility from the flours depended on processing, with minor influence of the raw material, fiber content and granulometry. The whiter and the smaller the granulometry of the dry cassava flours, the better they showed as potentially health benefiting.

Keywords:
Englyst method; amylase from porcine gastric mucosa; resistant starch

Sample	L*	a*	b*	Whiteness index
CA1	77.2 ± 2.0^ed	1.3 ± 0.0^j	8.8 ± 0.4^kj	75.5±1.8^e
CA2	83.0 ± 1.0^cb	1.7 ± 0.1ⁱ	9.7 ± 0.2^ji	85.0 ± 0.4^a
CA3	88.7 ± 0.6^a	1.0 ± 0.0^k	8.3 ± 0.6^k	81.0 ± 1.1^b
CA4	76.5 ± 0.2^e	5.3 ± 0.0^c	26.4 ± 0.1^d	64.2 ± 0.2^h
CA5	72.9 ± 3.0^f	2.7 ± 0.1^f	15.7 ± 0.4^g	68.6 ± 2.4^g
CA6	79.5 ± 0.5^d	3.4 ± 0.2^e	17.8 ± 0.2^f	72.6 ± 0.5^f
CA7	85.1 ± 0.4^cb	2.3 ± 0.0^g	15.1 ± 0.1^g	78.6 ± 0.3^dc
CA8	85.2 ± 1.3^b	1.7 ± 0.0ⁱ	12.5 ± 0.1^h	80.6 ± 0.9^cb
BCO1	83.3 ± 1.4^cb	0.7 ± 0.1^l	15.5 ± 1.1^g	77.2 ± 1.1^ed
BCO2	71.9 ± 3.1^gf	6.5 ± 0.2^b	40.3 ± 0.6^b	50.4 ± 1.3^j
BCO3	69.6 ± 3.2^g	8.8 ± 0.1^a	45.1 ± 1.1^a	44.9 ± 1.0^k
BCO4	78.9 ± 0.2^ed	5.3 ± 0.0^c	38.6 ± 0.1^c	55.7 ± 0.1ⁱ
BCO5	85.3 ± 0.3^b	0.2 ± 0.0^m	10.5 ± 0.4ⁱ	81.9 ± 0.5^b
BCO6	82.5 ± 0.9^c	1.2 ± 0.0^j	15.1 ± 0.4^g	76.9 ± 0.4^ed
BCA1	76.9 ± 1.3^ed	3.8 ± 0.2^d	19.7 ± 1.7^e	69.4 ± 2.1^g
BCA2	73.3 ± 1.3^f	2.1 ± 0.1^h	14.9 ± 0.7^g	69.4 ± 1.4^g
p-Brown-Forsythe**	0.69	0.84	0.89	0.73
p-Anova***	<0.0001	<0.0001	<0.0001	<0.0001

Samples	T0 (ºC)	Tp (ºC)	Tc (ºC)	ΔH (J/g)
CA1	64.7 ± 0.1^h	71.2 ± 0.3^fed	76.8 ± 1.3^f	3.7 ± 0.4^b
CA2	64.5 ± 0.3^h	70.1 ± 0.1^f	75.8 ± 0.4^g	3.4 ± 0.2^c
CA3	65.4 ± 0.1^g	70.8 ± 0^fe	77.5 ± 0.1^e	5.5 ± 0.1^a
CA4	68.1 ± 0.5^c	74.3 ± 0.2^ba	82.9 ± 0.4^a	2.3 ± 0.2^d
CA5	67.2 ± 0.3^ed	72.9 ± 0.1^dcb	78.6 ± 0.2^d	0.9 ± 0.1^gf
CA6	69.6 ± 0.4^a	75.0 ± 0.1^a	79.7 ± 0.5^c	0.6 ± 0.1^ih
CA7	65.8 ± 0.2^g	72.1 ± 0^edc	81.3 ± 0.1^b	1.7 ± 0.2^e
CA8	67.1 ± 0.0^ed	71.9 ± 0.1^fedc	78.5 ± 0.2^d	3.6 ± 0.1^cb
BCO1	67.9 ± 0.1^c	75.0 ± 0.1^a	82.7 ± 0.4^a	0.9 ± 0.1^gf
BCO2	68.6 ± 0.1^b	75.1 ± 0^a	83.3 ± 0.1^a	1.0 ± 0.1^gf
BCO3	62.9 ± 0.0ⁱ	67.6 ± 0.2^g	74.8 ± 0.6^h	0.7 ± 0.0^hg
BCO4	66.9 ± 0.3^e	71.9 ± 2.1^fedc	80.8 ± 0.3^b	1.0 ± 0.1^gf
BCO5	67.4 ± 0.6^d	70.3 ± 4.2^fe	80.7 ± 0.6^b	0.9 ± 0.1^gf
BCO6	66.4 ± 0.1^f	73.5 ± 0.1^cba	80.9 ± 0.1^b	1.0 ± 0.1^f
BCA1	65.7 ± 0.0^g	67.9 ± 0.0^g	73.0 ± 0.0ⁱ	0.3 ± 0.0ⁱ
BCA2	62.2 ± 0.0^j	71.0 ± 0.0^fed	78.9 ± 0.2^d	0.5 ± 0.0^ih
p-Brown-Forsythe**	0.44	0.12	0.66	0.23
p-Anova***	<0.0001	<0.0001	<0.0001	<0.0001

Instituto de Tecnologia do Paraná - Tecpar Rua Prof. Algacyr Munhoz Mader, 3775 - CIC, 81350-010 Curitiba PR Brazil, Tel.: +55 41 3316-3052/3054, Fax: +55 41 3346-2872 - Curitiba - PR - Brazil
E-mail: babt@tecpar.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] *Correspondence: demiate@uepg.br; Tel.: +55-42-32203268 (I.M.D.).