Succinylation improves the slowly digestible starch fraction of cardaba banana starch. A process parameter optimization study

The study investigated the improvement of slowly digestible starch fraction of cardaba banana via octenyl succinic anhydride(OSA)modification process.A nonlinear(Response surface methodology[RSM]and artificial neural network[ANN])and linear(partial least square[PLS])modelswere employed and their predictabilitywas compared.The result revealed that all the modelling techniques were accurate in predicting the experimental process.The optimized RSM values for the production of slowly digestible starch(SDS)fraction were OSA concentration of 4%,reaction time of 47.49 min,and pH of 10 with a predicted SDS value of 44.64%.Among the modelling techniques,ANNwas adjudged as the predictivemodel for improving the SDS yield.The regression coefficient coupled with the variable important in the projection(VIP)values of the PLS model indicated that the OSA concentrationwas themost important factors responsible for high SDS yield.Finally,a structural comparison of the optimized starch against native starch revealed the formation of high ordered crystalline structure of the starch due to the impregnation of the modifying agent to the hydroxyl group of the cardaba banana starch.

The Effect of Potato Varieties and Processing Methods on Glycemic Response

In order to identify those potatoes which exert a low glycemic impact after processing, eight early potato varieties and four processing methods were evaluated for their total starch content, amylose content, rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS), estimated glycemic index (eGI), glycemic load (eGL) as well as their relationship among each other. While all these profiles were highly dependent on the potato variety and processing methods, all the eight varieties were classified as low GL foods (p ≤ 0.05). A strong positive correlation was observed between eGI and RDS (r = 0.84, 0.79, and 0.74) for retrograded and reheated, baked and microwaved varieties, respectively), whereas a moderate negative correlation was observed between eGI and RS for retrograded and reheated (r = -0.39) and microwaved (-0.37) varieties (p ≤ 0.05). On the basis of these findings, it can be concluded that potato variety, processing methods, and starch characteristics define the eGI and eGL. Furthermore, for the varieties examined, the present study identified RDS as a major starch factor contributing to eGI.

Net energy,energy utilization,and nitrogen and energy balance affected by dietary pea supplementation in broilers

Pea starch consists predominantly of C-type of amylopectin chain which is more resistant to digestive enzymes than A-type of starch thus slowly digested in poultry.It was hypothesized that the presence of slowly digested pea starch in broiler diets will increase net energy and the efficiency of energy utilization in broilers.Two experiments were performed to investigate starch digestibility of pea at different in-cubation times(in vitro study)and the effect of dietary pea on heat increment and net energy in broilers using an open-circuit respiratory calorimetry system(in vivo study).One-day-old Ross 308 male broilers were fed a common starter crumble from d 1 to 10 and standard grower diets thereafter.At d 21,birds were transferred to the chambers each housing 2 birds.Each treatment was replicated 6 times with 2 identical runs of 3 replicates per treatment.A wheat-soybean meal-based diet was used as a control and the treatment diet contained 500 g of pea/kg pea.In vitro study showed that pellet processing increased(P<0.001)starch digestibility,particularly at shorter times for wheat and a much larger response for pea.Birds offered the pea-based diet had lower(P=0.002)feed intake,lower(P=0.020)body weight gain,but a similar(P>0.05)FCR compared to those offered the wheat-based diet.Net energy(NE)and apparent metabolizable energy(AME)values were higher in the pea-based diet than in the wheat-based diet(P-0.037 for NE and P-0.018 for AME).Heat production,respiratory quotient,heat increment of feed,efficiency of utilization of gross energy for AME,and efficiency of utilization of AME for NE did not differ(P>0.05)between the 2 treatments.There was no effect(P>0.05)of pea on the total tract di-gestibilities of dry matter,crude protein and ash,but the total tract digestibility of starch was higher(P-0.022)in the pea-based diet compared to the wheat-based diet.This study provides insight into the energy metabolism of broilers offered a pea-based diet and indicates that dietary pea supplementation increases dietary AME and NE but has no effect on heat increment of feed and the efficiency of energy utilization in broilers.