Low Amylopectin Research Articles

Rapid screening of sixty potato cultivars for starch profiles to address a consumer glycemic dilemma.

Potatoes are a dietary staple consumed by a significant portion of the world, providing valuable carbohydrates and vitamins. However, most commercially produced potatoes have a high content of highly branched amylopectin starch, which generally results in a high glycemic index (GI). Consumption of foods with high levels of amylopectin elicit a rapid spike in blood glucose levels, which is undesirable for individuals who are pre-diabetic, diabetic, or obese. Some cultivars of potatoes with lower amylopectin levels have previously been identified and are commercially available in niche markets in some countries, but they are relatively unavailable in the United States and Latin America. The high glycemic index of widely available potatoes presents a problematic "consumer's dilemma" for individuals and families that may not be able to afford a better-balanced, more favorable diet. Some native communities in the Andes (Bolivia, Chile, and Peru) reportedly embrace a tradition of providing low glycemic tubers to people with obesity or diabetes to help people mitigate what is now understood as the negative effects of high blood sugar and obesity. These cultivars are not widely available on a global market. This study examines 60 potato cultivars to identify potatoes with low amylopectin. Three independent analyses of potato starch were used: microscopic examination of granule structure, water absorption, and spectrophotometric analysis of iodine complexes to identify potato cultivars with low amylopectin Differences among cultivars tested were detected by all three types of analyses. The most promising cultivars are Huckleberry Gold, Muru, Multa, Green Mountain, and an October Blue x Colorado Rose cross. Further work is necessary to document the ability of these low amylopectin cultivars to reduce blood glucose spike levels in human subjects.

The Physicochemical Characterization, Gelatinization Profile, and Proximate Analysis of Sweet Potato Starch (Ipomoea batatas L.) White, Yellow, and Purple

Sweet potato (Ipomoea batatas L.) has a considerable potency to be developed in Indonesia because of its high nutritional content and spacious application of sweet potato starch in food and non-food fields. Physicochemical characterization, gelatinization profile, and proximate analysis of sweet potato starch white, yellow, and purple has been carried out. Initially, extraction of starch from white, yellow, and purple sweet potato flour was done using a maceration technique. The starch extract was then analysed to determine its physicochemical properties such as pH, density, boiling point, melting point, swelling capacity, and solubility in water, as well as morphological surface using Scanning Electron Microscopy (SEM). The gelatinization profile of sweet potato starch was measured using the Rapid Visco Analyzer (RVA). The proximate composition of sweet potato starch was also determined. The results showed that yellow sweet potato starch has a high amylose content of 28.17% which thus leads to difficulty in absorbing water, increasing the gelatinization temperature and affecting the structural stability of the starch. The molecular structure of amylose and amylopectin is the main factor influencing the determination of the physicochemical characterization of sweet potato starch. Proximate analysis of sweet potato starch showed high content of amylose (28.17%), water (17.03%), and protein (5.21%) with low amylopectin (71.83%), minerals (1.09%), fat (0.09%), and carbohydrates (76.9%) content. The three varieties of sweet potato show extraordinary potential in food industrial applications because they play a huge part in deciding the suitability of sweet potato starch for specific requirements and interest in developing new and remarkable starch sources.

Rice noodle quality is structurally driven by the synergistic effect between amylose chain length and amylopectin unit-chain ratio

Chewiness, slipperiness, and rapid rehydration are satisfactory qualities for rice noodles. These qualities are dependent on rice starch structure. However, the synergistic effect of fine structure of amylose (AM) and amylopectin (AP) on rice noodle quality remains unclear. In this work, six rice varieties, three from early indica and three from late indica, with similar amylose content for each pair were analyzed to assess the synergistic effects between AM and AP fine structures. The results showed that the combination of amylose long-chains and a low amylopectin unit-chain (APC) ratio favored the maintenance of relatively intact starch granules, resulting in a higher die expansion ratio and improvement of the mechanical properties of rice noodles (Hardness varied from 403 g to 1627 g). Meanwhile, higher die expansion was associated with a larger rehydration ratio. These results suggest that the synergistic effect between AM and AP fine structures significantly affects rice noodles' quality.

Effect of Some Chemical Mutagens on Nutrient Compositions of Sweetpotato (Ipomoea batatas (L.) Lam)

Effects of sodium azide (SA) and colchicine (COL) (chemical mutagens) on some nutrient compositions of four varieties of sweetpotato (Butter milk, TIS87/0087, UMUSPO/3 and UMUSPO/1) were investigated at the Biotechnology Laboratory of the National Root Crops Research Institute Umudike, Nigeria. The parent plants were treated with sodium azide and colchicine mutagens at concentrations of 0%, 0.03%, 0.05% and 0.07%. Storage roots of the M2V2 generations from the mutant plants were used for the nutrient composition analysis using recommended standard procedures. Nutrient traits studied were: moisture content (%), dry matter content (%), amylose and amylopectin contents (%), starch yield (%), starch content % based on fresh weight and starch content % based on dry weight. Mutants with higher dry matter content than the control were observed in TIS87/0087 treated with SA and COL 0.03%. SA and COL 0.05% produced mutants with higher amylose content (and lower amylopectin) than the control in TIS87/0087. UMUSPO/3 treated with SA 0.03% and SA 0.05% produced mutants with higher values for amylose content (and lower values for amylopectin) than the control; the same variety treated with colchicine (COL 0.05%), recorded higher value for amylose content (and lower value for amylopectin) than the control. These findings showed that sodium azide and colchicine mutagens were potent in inducing variations in nutrient composition of sweetpotato.

Physicochemical, morphological, functional, and pasting properties of potato starch as a function of extraction methods

The potato starch extracted by physical, chemical, and enzymatic methods were analyzed for physicochemical, morphological, functional, and pasting properties. In the physical extraction methods, T1 (water at 30 °C) was found better in starch yield, water absorption capacity (WAC), and whiteness. In the chemical extraction methods, starch from T5 (NaOH-0.25%) had higher WAC, and lower ash content. The starch from T7 (SDS-ME-2%) had higher amylose, starch purity, and lower amylopectin, moisture, fat content. The starch from T11 (NaOCl-5.25%) had higher starch whiteness value. In the enzymatic extraction methods, starch from T13 (cellulase-0.15%) had higher starch yield. Further, the physical (T1), chemical (T5, T7 and T11) and enzymatic (T13) methods were used in combination and had shown the better physicochemical and morphological characteristics of starch. The starch from combined method (T14) had significantly higher yield (12.4%), WAC (259%), swelling power (40.3%), solubility (23.6%), purity (87.3%), and whiteness (95.2%). The starch from combined method also had significantly lower phosphorus (81.7%), protein (0.30%), fat (0.29%), ash (0.26%), crude fiber (0.15%) content, and syneresis (18.8%). The starch from combined method had resulted in the better starch granule structure, pasting properties than most of the other treatments. So, the physical, chemical, and enzymatic treatments in combination can be used for extraction of high-quality starch from potato.

Identification of rice varieties specialties in Vietnam using Raman spectroscopy

AbstractThe characteristics and quality of rice are significantly affected by its variety. However, discrimination between varieties is an urgent but difficult and time‐consuming effort in Vietnam. In this study, an effective and reliable identification method was established by Raman spectroscopy (RS). Total Raman spectra of 32 rice samples were acquired from 400 to 1600 cm‐1 and the sensitive fundamental vibrations of less polar groups and bonds in rice were analyzed. Initially, the raw Raman spectra were processed by standard normal variety (SNV) combined with Savitzky Golay (SG) smoothing algorithm. The positive influence of SNV‐SGD2 on the ability to classify rice varieties has been confirmed by principal component analysis (PCA). Next, multivariate analysis methods included PCA, hierarchical cluster analysis (HCA), and K‐nearest neighbor (KNN), that have been compared with each other on the ability to classify rice varieties. All three methods give the ability to classify four rice varieties very well. The PCA method identifies four main factors were starch chains, amylose, amylopectin, and protein contents which are used to distinguish among four rice varieties. While HCA only distinguishes well between rice with high and low amylopectin content and does not provide the main components.

Effect of Accelerated Retting Process on Physiochemical and Pasting Properties of Cassava (Manihot esculenta Crantz) Flours

Aims: To compare the physicochemical (water, total titratable acid, amylose and amylopectin contents), functional (swelling and solubility powers) and pasting characteristics of cassava flour retted in two different ways.
 Study Design: Flours were produced from two cassava cultivars subjected to natural and accelerated fermentations using a multi-strain mixed starter.
 Place and Duration of Study: Department of Microbiology of the University of Yaounde 1 and Department of Food Science and Nutrition at the University of Ngaoundere, both in Cameroon, between November 2019 and February 2020.
 Methodology: The cassava roots of each cultivars were divided into two groups and fermented by submerging peeled roots in tap water. One group of each cassava cultivar was inoculated with 1% (w/w) of the starter, while the other was subjected to a spontaneous fermentation. Retting stopped after the softening of the roots; that is after twenty-six hours for the inoculated groups, and after seventy-two hour for the control groups. The fermented roots were then squeezed, dried and grounded in a blender. Flours obtained were subjected to physicochemical, functional and pasting analysis.
 Results: Flours produced in accelerated fermentation (AF) were characterized by their low amylopectin contents (46.59% and 43.57%), swelling power (6.71% and 7.56%), solubility (6.03% and 7.96%), and peak viscosity (6182 cP and 5676 cP) for Six-mois and Mintol-meko flours respectively. Whereas setback viscosity (1032 cP and 1068 cP), stability (0.27 and 0.24) and final viscosity (3565 cP and 3566 cP) of flours from natural fermentation (NF) were lower than those from AF.
 Conclusion: The accelerated fermentation reduces the tendency of paste to downgrade, that is responsible for staling in baked products and could therefore produce flours that are less fluid.

Karakterisasi Genotipe F1 dan F2 Jagung Varietas Srikandi Putih dan Lokal Pulut Pada Jarak Tanam yang Berbeda

<p>The crossing between Srikandi Putih corn varieties which have high production potential and protein content with local pulut corn which has high amylopectin levels is expected to produce superior offspring. This study aimed to determine the character of F<sub>1</sub> and F<sub>2</sub> results of crossing of Srikandi Putih variety with local Pulut corn (waxy corn) at different planting distance. This research was conducted in the Experimental Farm of the Bajeng Cereals Crop Research Institute, South Sulawesi Province, from May-August 2018. This method used was Split Plot Design, consisting of Main Plots, namely planting distance (70 cm x 20 cm and 70 cm x 30 cm) and Sub Plots, namely Varieties (Srikandi Putih, Local Pulut, F<sub>1</sub> and F<sub>2</sub>). The results showed that genotype significantly affected plant height, seed production per hectare, amylopectin content and seed protein content, and genotype had very significant effect on number of leaves, ear length, ear diameter, seed weight per plant and seed weight per plot. Planting distance has a very significant effect on seed weight per plot and the best was 70 cm x 20 cm. This is due to the number of populations at 70 cm x 20 cm planting distance more than 70 cm x 30 cm. Genotype interaction and planting distance have a very significant effect on seed weight per plant. Srikandi Putih variety was the best genotype for growth, production and protein content parameters while the best amylopectin content parameter was local Pulut. Srikandi Putih variety was potential for growth and production as well as high protein content, but low amylopectin levels while local Pulut has high potential for amylopectin levels but low growth and production potential. The best combination of growth, production, protein and amylopectin content was in F<sub>1</sub> and F<sub>2</sub> genotypes.</p>

Potential industrial utilization of starches extracted from new yellow cassava varieties

Industrials generally utilize rice, wheat, corn and potato starches because of their well-known physicochemical and functional properties. In this study, starches of some improved cassava varieties were analyzed in order to detect those revealing potentialities and aptitude for industrial exploitation. For this, morphological, physicochemical and functional characteristics of these starches were evaluated. All the starches were composed of ovoid and conical granules with truncated sides bearing one or several holes. They contained relatively low amount of small granules (< 10 μm) with low amylopectin content. All starches showed very strong water absorption capacity with the strong value recorded by V53 (122.52 ± 1.57 %) and the lowest by V63 (104.84 ± 0.55 %) and began gelatinizing early (50–55 °C). However, physicochemical and functional characteristics significantly varied from a starch variety to another. Hence, V53 (32.47 ± 0.54 g/g), V63 (29.41 ± 0.64 g/g) and V71 (28.58 ± 0.55) varieties which recorded low small granules content showed the earliest (80 °C) and strongest swelling power peak. In addition, these varieties showed the lowest syneresis values at 4 °C (V53 (0.01%) and V63 (0.6%) and at – 15 °C V71 (0.01%)) during the first week of experimentation (V71) and during the four weeks of experimentation (V53 and V71). The highest values of paste clarity were highlighted by V23 (63.00 ± 0.3 %) and V53(85.85 ± 0.5 %), respectively. All the studied cassava starches varieties showed interesting physicochemical and functional characteristics which could be exploited in food and non-food industries. Keywords: New yellow Cassava varieties, starches, physicochemical characteristics, functional properties, industrial utilization

Starch-based coatings for colon-specific drug delivery. Part I: The influence of heat treatment on the physico-chemical properties of high amylose maize starches

In this study, the changes in the physico-chemical properties of different high amylose maize starches, i.e., Hylon ® VII, Hylon ® V and IM-DS acetate starch, were studied prior and after heat treatment used in the preparation of film coatings (WO 2008/012573 A1). Characterisation of the unprocessed maize starches was carried out with regard to the outer particle morphology, particle size distribution, specific surface area, moisture content, apparent particle density, swelling, polarised light microscopy, Fourier Transform Infrared (FT-IR), X-ray powder diffraction and modulated Differential Scanning Calorimetry (mDSC). Pure amylopectin and low amylopectin samples (LAPS) were also used to aid the interpretation of the results. The effect of heat processing was evaluated in terms of degree of crystallinity, FT-IR and mDSC. Enzymatic digestibility of both processed and unprocessed maize starches was estimated qualitatively using various α-amylases resembling those present under in vivo conditions. A significant decrease in the degree of crystallinity of the dried samples after processing was observed, in particular for amylopectin. Only LAPS and Hylon ® VII samples showed differences in their thermal behaviour upon heat treatment, thus suggesting that a minimum amount of amylose is required for an effect to be detectable. High amylose starches maintained a well-ordered arrangement of their macromolecular chains, as was seen by X-ray and FT-IR studies. This effect could be explained by a formation of retrograded forms of the starches. The retrograded starches were found to be less digestible by various types of amylase, in particular those found in the upper intestines, indicating that the formation of a butanol complex as claimed elsewhere is not essential in the preparation of colon delivery devices.

Production of very-high-amylose potato starch by inhibition of SBE A and B.

High-amylose starch is in great demand by the starch industry for its unique functional properties. However, very few high-amylose crop varieties are commercially available. In this paper we describe the generation of very-high-amylose potato starch by genetic modification. We achieved this by simultaneously inhibiting two isoforms of starch branching enzyme to below 1% of the wild-type activities. Starch granule morphology and composition were noticeably altered. Normal, high-molecular-weight amylopectin was absent, whereas the amylose content was increased to levels comparable to the highest commercially available maize starches. In addition, the phosphorus content of the starch was increased more than fivefold. This unique starch, with its high amylose, low amylopectin, and high phosphorus levels, offers novel properties for food and industrial applications.

Low Temperature Sweetening in Susceptible and Resistant Potatoes: Starch Structure and Composition

ABSTRACTStarch isolated from ND 860–2 potatoes, which were resistant to chillsweetening, had higher amylose and lower amylopectin as well as a higher crystallinity as compared to starch isolated from Norchip potatoes, which were susceptible to low temperature sweetening. ND 860–2 starch exhibited greater resistance to α‐amylase attack and amorphous swelling as well as higher gelatinization temperatures and onset swelling temperatures than starch isolated from Norchip. Examination of starch granule structure using bright field light microscopy indicated crystalline concentric rings in ND 860–2 not seen in Norchip. Scanning electron microscopy of granules incubated with a‐amylase indicated more intact ND 860–2 starch granules compared to Norchip. These data strongly suggest that starch granule composition is a factor differentiating the low‐temperature sweetening sensitive cultivar from the resistant potato seedling.