Fourier-transform infrared spectroscopy: An inexpensive, rapid, and less-destructive tool for starch and resistant starch analysis from pulse flour

Abstract

Pulse crops are a rich source of resistant starch (RS) (5–7 g/100 g), a prebiotic carbohydrate that promotes gut health. The standard method to measure total starch (TS) and RS is through enzymatic assay; however, this is both time consuming and expensive. Fourier-transform mid-infrared (FT-MIR) spectroscopy is a high-throughput, cost-effective method to quantify nutritional traits in seeds, but models have not been developed for starch in pulse crops. Therefore, this study aimed to develop and validate an FT-MIR chemometric technique to estimate TS and RS in dry pea (Pisum sativum L.), chickpea (Cicer arietinum L.), and lentil (Lens culinaris, Medikus) flours to accelerate global pulse breeding efforts, support industrial carbohydrate utilization, and develop healthier food-feed calorie contents. Breeding lines were selected to capture the diversity of starch concentrations in each crop and were analyzed using an enzymatic assay. Models for each trait–crop combination were calibrated using partial least squares regression, resulting in R2 and root means square error of prediction ranging from 0.91 to 0.96 and 0.16 to 4.0 g/100 g, respectively. These results demonstrate that FT-MIR spectroscopy is a promising tool for estimating TS and RS concentrations in pulse crops at a reduced analysis time and cost, expediting plant breeding and starch use efforts in the food processing industry.