Isolation, partial characterization and in vitro digestion of starch from Ariopsis peltata and Lagenandra toxicaria tuber

The starch from two aroid tuber viz. Ariopsis peltata and Lagenandra toxicaria were isolated and evaluated for their morphological, physical and chemical properties. The tubers of these plants are used as food and medicine by the indigenous communities. The starch yield from A. peltata tuber was 25 ± 1.7% with an amylose content of 10 ± 0.9%, while the tuber of L. toxicaria contained 28 ± 6.5% starch with 15 ± 0.5% of apparent amylose in it. The starch isolated from both the tubers was highly pure (99%) starch exhibiting an A-type X-ray diffraction pattern. The starch granules of L. toxicaria were of various shapes and exhibited a smooth surface without any cleft or break. While the starch granules of A. peltata were spherical with smooth surface, as well as rough surface. The breaks and clefts were apparent on the rough-surfaced granules. The gelatinization temperature range for A. peltata and L. toxicaria starch is approximately 23 °C and 19 °C respectively. A. peltata starch showed higher thermal stability compared to L. toxicaria starch and either of the starch was rapidly digestible as evident from in vitro digestion study. The physicochemical properties of both the starches render them stable to withstand extreme processing. Besides they also mimic simple sugar in digestibility. So it can be utilized as a substitute for simple sugars in brewing and pharmaceutical industries.

The influence of protein concentration on key quality attributes of chickpea-based alternatives to cheese

In response to consumer demands, plant protein ingredients are increasingly being used in the formulation of plant-based alternatives to cheese. The aim of this study was to determine the influence of protein concentration on key quality attributes of chickpea-based alternatives to cheese. Moreover, the age-induced changes in such attributes were assessed, with samples analysed after 1 month of storage. After characterisation of the ingredients, the chickpea-based formulations were prepared by blending chickpea flour and protein concentrate in different proportions to obtain four samples of increasing protein content (i.e., 8.68-21.5%). Formulations were developed at pH ∼4.5, and a moisture content of 50%, with shea butter used to obtain 15% fat content. The differential scanning calorimetry thermograms of the samples showed a main peak around 30 °C, corresponding to transition of the shea butter, and a smaller peak around 70 °C related to starch gelatinisation. Analysis of microstructure showed formation of a protein matrix with more extensive protein structure at high protein concentration. Furthermore, none of the chickpea-based samples melted under the testing conditions and all samples showed increasing values for adhesiveness, springiness and cohesiveness with increasing protein content. However, hardness was the highest for the sample with the lowest protein content, likely due to starch retrogradation. After storage, hardness increased further for all samples. This work improves our understanding of the role of chickpea protein in developing plant-based alternatives to cheese and the challenges therein.

Composition, morphology and physicochemical properties of starches derived from indigenous Ethiopian tuber crops: A review

Starch is a key food ingredient that can be extracted from roots, tubers, cereals, legumes and used in a variety of industrial applications. The issue of starch has received considerable critical attention. Most conventional sources of starch are being overexploited, it is necessary to investigate new botanical sources of starch to relieve pressure on traditional sources. Indigenous Ethiopian tuber crops can represent unexploited sources of starch with interesting characteristics in terms of potential uses as starch-based foods. It comes in a variety of shapes, sizes and properties allowing for a wide range of applications with high technological value in both the food and non-food industries. Compared to common starches, these starches have far fewer studies on their food and industrial applications. In the future, tubers grown Ethiopia could become another source of starch for the processor. This review summarizes current knowledge about the composition, structure, and physicochemical properties of Ethiopian tubers starches, intending to recommend future research to improve their use in the food industry. In the future, more in-depth work will be needed to reveal the mechanism of modification involved for structural change to use these starches for different purposes.