Shape Of Starch Granules Research Articles

NegFluo, a Fast and Efficient Method to Determine Starch Granule Size and Morphology In Situ in Plant Chloroplasts.

Starch granules that accumulate in the plastids of plants vary in size, shape, phosphate, or protein content according to their botanical origin. Depending on their size, the applications in food and nonfood industries differ. Being able to master starch granule size for a specific plant, without alteration of other characteristics (phosphate content, protein content, etc.), is challenging. The development of a simple and effective screening method to determine the size and shape of starch granules in a plant population is therefore of prime interest. In this study, we propose a new method, NegFluo, that combines negative confocal autofluorescence imaging in leaf and machine learning (ML)-based image analysis. It provides a fast, automated, and easy-to-use pipeline for both in situ starch granule imaging and its morphological analysis. NegFluo was applied to Arabidopsis leaves of wild-type and ss4 mutant plants. We validated its accuracy by comparing morphological quantifications using NegFluo and state-of-the-art methods relying either on starch granule purification or on preparation-intensive electron microscopy combined with manual image analysis. NegFluo thus opens the way to fast in situ analysis of starch granules.

Comparison of chemical, functional and morphological characteristics of jackfruit (Artocarpus heterophyllus Lam.) (J33) seed starch and commercial native starches

This study aimed to compare the starch isolated from jackfruit seed specifically from J33 variety with the commercial native potato, tapioca and waxy maize starches in terms of their chemical, functional and morphological properties. The infra–red spectra, bond bending and stretching of all samples were analysed using FTIR spectrometer within range of 4000 - 400 cm−1. Least gelation concentration (LGC), swelling power (SP) and solubility were determined as functional properties of the starches. Scanning electron micrograph (SEM) was used for characterisation of starch granules morphology. FTIR measurement shows aromatic compounds detected in jackfruit seed starch (JSS). LGC displays capability of JSS to form gel at 10% which is better than potato starch. SP and solubility of JSS have no significant differences over the temperature changes. SEM image of JSS exhibits bell and round shape of starch granule. Thus, JSS can be a good source of starch in future and help in reducing waste by turning into beneficial product.

Development of starch nanoparticles based composite films from non-conventional source - Water chestnut (Trapa bispinosa)

In the present study, starch was isolated from a non-conventional source (water chestnut) and various physicochemical properties were investigated. Nano starch was prepared by adopting the acid hydrolysis method having a yield of 27.5%. Particle size distribution of native and nano starch was 5559 nm and 396 nm. The unique feature of water chestnut starch was the shape of starch granule that looked oval, ellipsoidal, mixed with spherical granules without cracks and smooth surface. While the water chestnut nano starch appeared as an agglomerated form with irregular and rough surface. Water chestnut starch nanocomposites films with varying concentrations of starch nanoparticles (SNPs) were synthesized by a solution casting method. The thickness, moisture content, water vapour transmission rate, water solubility, burst strength of native starch and nano starch composite films were evaluated. The results showed that native starch film had thickness (0.041 ± 0.07 mm) moisture content (4.17 ± 0.32%), water vapour transmission rate (4.678 × 10−3 ± 0.42 g−2 s−1), water solubility (35.71 ± 0.17%) and burst strength (976.4 ± 12.47 g), respectively. The incorporation of SNPs results in an increase in thickness and burst strength while moisture content, water vapour transmission rate and solubility of films were decreased with the increase in the concentration of SNPs which is essential features of a good package.

Thin layer drying kinetics of Banana var. Monthan (ABB): Influence of convective drying on nutritional quality, microstructure, thermal properties, color, and sensory characteristics

AbstractBanana with good amount of resistant starch (RS) offers greater benefit to human health. Studying the dehydration mechanism of the raw banana slice is very important for subsequent processes and quality of the product. Thus the study was aimed to investigate the influence of varying temperatures viz., 45, 55, and 65°C in a convective dryer on thin layer drying kinetics and to infer their influence on the rheological properties coupled thermal and sensory quality. Time for reducing the moisture content from the initial 71.2 ± 0.2% to a final 4.66–6.13% was found to be 270, 210, and 150 min for the drying temperatures 45, 55, and 65°C, respectively. Moisture ratio decreased exponentially with an increase in drying time. Page and logarithmic models obtained highest r2, lowest chi‐square values and least root mean square error and better reflected drying mechanism of banana slices. Improved rehydration ratio (1:2.4) and RS content (36.26%) was observed with the drying temperature of 55°C. Higher water absorption capacity (WAC) was observed in 55°C (4.86%). Swelling power of the flour was maintained to 4–6% till 70°C but it reached to 22% with the increase in temperature to 90°C. Thermal properties and microstructure of flour differed significantly with the temperatures. The lower value for whiteness index with low temperature drying reflected the better drying than at higher temperatures. Dehydration at 55°C was superior with nutrients like ascorbic acid. The banana flour had the rod shaped starch granules and traces of protein in its surface as evidenced. Irregular spherical shape, surface dents, and shrinkages were observed in powders dehydrated with high temperature (>65°C). Equilbrium relative humidity (ERH) studies revealed that 13.27 and 15.23% were the danger and critical point, respectively, for the banana flour. Descriptive sensory scores of the banana flour endorsed that dehydration at 65°C was found superior to other temperatures.Practical applicationsBanana flour offers greater potential to increase the resistant starch (RS) content in the food products besides adding minerals and basic nutrients. Drying process should retain the characteristics of fresh fruits by minimizing the cellular and structural changes during the drying. Mathematical modeling offers scope to set the variables which are influencing the drying of banana slices. The dried banana flour could be a replacement or supplement for various formulations. With the better physical properties like swelling capacity and enthalpy along with high RS, banana flour allow the formation of low bulk, high‐fiber products like pasta, noodles, and healthy functional foods with improved sensory descriptors. Banana flour‐based enterprises could be started in places where banana is cultivated and large sum of produced bananas are getting wasted due to poor postharvest management.

SbRFP1 regulates cold-induced sweetening of potato tubers by inactivation of StBAM1

Potato cold-induced sweetening (CIS) is a major drawback restricting potato process industry. Starch degradation and sucrose decomposition are considered to be the key pathways in potato CIS. Our previous study showed that the RING finger gene SbRFP1 could slow down starch degradation and the accumulation of reducing sugars (RS) through inhibiting amylase and invertase activity in cold-stored tubers. However, the regulation mechanism of SbRFP1 is not clear. In this paper, we first proved that SbRFP1 could promote starch synthesis and modify the shape of starch granules. By further yeast two hybrid, GST-pull down and inhibition of enzyme activity assays, we confirmed that SbRFP1 could slow down the transformation of starch to RS in tubers mainly through the inhibition of β-amylase StBAM1 activity. SbRFP1 was also proved to possess E3 ubiquitin ligase activity by ubiquitination assay. Thus, SbRFP1 may regulate the accumulation of RS in cold-stored tubers by ubiquitination and degradation of StBAM1. Therefore, our study reveals the regulatory mechanism of SbRFP1 in the process of CIS and provides more powerful evidence for the effect of starch degradation on potato CIS.

Characteristics of resistant starch in water chestnut flour as improved by preconditioning process

ABSTRACT Before cracking, subjecting water chestnuts to pre-conditioning is a common practice. However, the existing practice of pre-conditioning has no scientific rationale and therefore leads to low flour recovery and poor quality. Thus, the aim of the present research work was to optimize the pre-conditioning process for water chestnuts and to analyze the efficacy of optimized process as a means to increase the resistant starch content and reduce the glycemic index in water chestnut flour. Central composite rotatable design was used to determine the effect of water chestnut:water ratio, water temperature and pre-conditioning time on yield and brightness (L* value) of flour. Optimization of pre-conditioning process was done by response surface of desirability function. Regression models for both the product responses were highly significant (p < 0.0001) with high coefficient of determination (R 2 > 0.95). Scanning electron microscopy (SEM) showed compact, smooth and oval shaped starch granules with crystalline network in preconditioned water chestnut flour. FTIR studies also indicated higher absorbance ratio of 1047/1022 cm−1 for preconditioned water chestnut flour which further authenticated the SEM findings. Subjecting water chestnuts to optimized conditions of pre-conditioning (i.e., water chestnut:water ratio 1:1.5; water temperature 87.85̊C and pre-condition time 45 min), also increased the resistant starch content and lowered the glycemic index and glycemic load of the water chestnut flour.

Morphometrics of Starch Granules From Sub-Saharan Plants and the Taxonomic Identification of Ancient Starch

The assumption that taxonomy can be ascertained by starch granule shape and size has persisted unchallenged since the late nineteenth and early twentieth century biochemistry. More recent work has established that granule morphological affinity is scattered throughout phylogenetic branches, morphotype proportions vary within the genus, granules from closely related genera can differ dramatically in shape, and size variations do not reflect phylogenetic relationships. This situation is confounded by polymorphism at the species and tissue level, resulting in redundancy and multiplicity. This paper classifies morphological features of starch granules from 77 species, 31 families, and 22 orders across three African ecoregions. This is the largest starch reference collection published to date, rendering the dataset uniquely well suited to explore i) the diagnostic power of unique morphometric classifiers and their frequency, ii) morphotypes that cut across taxonomic boundaries, and iii) issues surrounding the minimum counts needed to accurately reflect granule polymorphism, variability, and identification. In a collection of 23,100 granules, taxonomic identification occurred very rarely. In the instances it did, it was at the species level, with no occurrences of a single morphotype or complement identifying all species within a family or genus. Some families cannot be uniquely identified, and morphometric types are shared despite taxonomic distance for three quarters of the taxa. However, this reference collection boasts 98 unique identifiers located in the Arecaceae, Convolvulaceae, Cyperaceae, Dioscoreaceae, Fabaceae, Musaceae, Pedaliaceae, Poaceae, and Zamiaceae. Therefore, the identification of starch granules is possible in some cases only.

Rheological measurements of composite flour containing Jackfruit (Artocarpus heterophyllus Lam.) flesh flour and its identification by pattern recognition methods

Jackfruit flour was significantly (p < .05) different from other flours due to its highest water absorption capacity (WAC) (1.57 g/g), particle size (PS) (384.984 µm) and lowest loss factor (tanδ), foaming stability (FS) (32.6%). The different blends consisting of jackfruit flour at 0.5%, 1%, 5%, 10%, 20%, 30% levels with equal proportions of rice and pigeonpea flour were prepared. The higher the substitution of jackfruit flour in blends, PS and WAC were increased whereas peak viscosity, trough viscosity, relative crystallinity, oil absorption capacity, foaming properties were decreased. A mixture of spherical, polyhedral and irregular shaped starch granules with less smooth granule surfaces can be observed using scanning electron microscopy. Micrographs of blends showed swollen and slightly elongated starch granules with distorted structure. Pattern recognition methods such as principal component analysis and linear discriminate analysis were performed to classify jackfruit flesh flour, rice flour and pigeonpea flour based blends on the basis of rheological, functional, microstructural and pasting properties. The variables like setback viscosity, FS, tanδ, final viscosity and WAC exhibited higher discrimination power.

Physicochemical properties and in vitro digestibility of high hydrostatic pressure treated waxy rice starch

Waxy rice starch slurry (10%, w/w) was treated with high hydrostatic pressure (HHP) (100–600 MPa) for 20 min and morphology, gelatinization property, X-ray diffraction pattern, semi-crystalline structure, and in vitro digestibility was determined. The morphology analysis showed that HHP treatment significantly affected the shape of starch granules. The thermal properties indicated an increase in gelatinization temperatures and decreased enthalpy with increasing pressure. However, compared with lower pressure, a complete gelatinization of starch was induced by 600 MPa. The lamellar repeat distance increased with increased pressure, while scattering peak disappeared at 600 MPa as a result of starch gelatinization. Based on the in vitro digestibility results of slowly digestible starch, HHP treatment at 400 MPa could be beneficial for improving the functionality of the waxy rice starch.

Contribution of zein content and starch characteristics to vitreousness of commercial maize hybrids

Fast, simple laboratory methods were used to analyze 22 maize samples varying in kernel vitreousness from 50.23% to 76.41%. Samples were analyzed in terms of zein content (53.86–86.37 g/kg endosperm DM), amylose content (190.76–259.77 g/kg endosperm DM), amylose to amylopectin ratio in starch (0.28–0.43), as well as starch granule size (10.95–14.89 μm in equivalent diameter) and starch granule shape (circularity, 0.85–0.94). More vitreous samples had higher zein and amylose content, as well as smaller and less circular starch granules. Nearly all grain traits on their own significantly affected vitreousness, and a multiple regression model to account for their combined effects was able to explain 61.8% of variability in kernel vitreousness. Zein content contributed most to the model, followed by starch granule projected area and circularity. In contrast, the amylose content contributed only 5.1% to the model. These results suggest that starch-protein interactions influence maize kernel vitreousness more strongly than starch molecular properties do.

Phosphorus Alters Starch Morphology and Gene Expression Related to Starch Biosynthesis and Degradation in Wheat Grain.

Phosphorus is an essential plant macronutrient which profoundly affects the yield and quality of wheat starch. In this study, scanning electron microscopy showed that P fertilizer amount (0, 46, and 92 kg P ha−1) had no significant effect on the shape of starch granules in wheat (cv. Xindong 20) grain. However, confocal laser scanning microscopy with 3-(4-carboxybenzoyl) quinoline-2-carboxaldehyde and methanolic merbromin stains indicated that P amount influenced the microstructure of the starch granules. Starch granules from the 46 kg P ha−1 treatment released significantly more reducing sugars than those from the 0 and 92 kg P ha−1 treatments during digestion with alpha-amylase and amyloglucosidase digestion. Phosphorus application (especially the 46 kg P ha−1 treatments) significantly increased the relative expression of genes related to starch synthesis (especially during early to mid-grain filling) and starch degradation (especially during mid- and late grain filling). Phosphorus application also increased the transcript abundance of amylase genes at the periphery of the endosperm. We propose that P application, especially the 46 kg P ha−1 treatment, enhanced channels in wheat starch granules. These channels facilitated the transport of substances required for starch biosynthesis, thus increasing starch accumulation in wheat endosperm. These results provide insight into the potential mechanisms through which P influences the microstructure and biosynthesis of wheat starch.

Evaluation of the green pea (Pisum sativum L.) collection for presence of carriers of r and rb mutations

Objective. To evaluate the green pea (Pisum sativum L.) collection in order to identify carriers of r and rb mutations in it. Methods. Pea accessions were grown in the field, and seeds were produced under controlled pollination. The starch granule shape was determined in micrographs taken with a computer digital microscopic camera DMC-300 through a Biolam-15 microscope (object lens × 40). The starch content was determined polarimetrically by the Evers method and the amylase content colorimetrically — by the BO Juliano method. The data were statistically processed using analysis of variance. Results. The effect of r and rb mutations on the starch content and fractional composition in pea seeds was confirmed. In smooth-seed accessions the average starch content was 39,9 %, and the amylose content in starch was 45,9 %, while in r mutation carriers these contents were 31 ,2 % and 67,6 %, respectively, and in rb mutation carriers — 26,9 % and 28,2 %, respectively. An accession with marrowfat seeds, roundish starch granules and a low content of amylose in starch was identified. It was established that this accession was a carrier of a recessive mutation that is not allelic to r mutation and coincides with rb mutation by the effect type. Conclusions. A new genetic source of starchmodifying monogenic rb mutation of pea was identified. It was involved hybridization with sources of r mutation to expand the genetic basis of pea cultivar breeding.Keywords: peas, Pisum sativum, genetic diversity, r, rb, seed phenotype, starch grain shape, starch content, amylose content.

Steady and dynamic shear rheology of starches from different oat cultivars in relation to their physicochemical and structural properties

ABSTRACTStarches isolated from eight oat cultivars were tested for their physicochemical, structural, and rheological properties. The isolated starches had low levels of ash and nitrogen contents with amylose ranging from 21.8 to 32.3 g/100 g. The amount of water released from starch gels decreased significantly (p < 0.05) with increase in freeze thaw cycle. The scanning electron micrographs revealed the presence of polygonal to irregularly shaped starch granules. All the starches exhibited A-type X-Ray diffraction pattern typically characteristic of cereal starches. The rheological properties of pastes were well described by the Herschel-Bulkley model at a shear rate of 0–100 s−1 (R2 > 0.99). The starch pastes behaved like a pseudoplastic fluid and exhibited shear thinning fluid characteristics with values of flow behaviour index considerably less than 1. Both the storage and loss moduli of the pastes increased sharply initially and then dropped after reaching the gelatinization peak. The magnitude of the dynamic rheological parameters varied significantly (p < 0.05) between the cultivars. All the starch pastes were highly elastic than viscous as evidenced by the lower tan δ values. Structure property relationships were established between starches using principal component analysis.

Physicochemical, thermal and functional properties of gamma irradiated chickpea starch

The study was conducted to evaluate the effect of gamma irradiation (0, 0.5, 1, 2.5, 5 and 10kGy) on physicochemical, functional and thermal properties of chickpea starch. Results revealed that the pasting properties showed a significant (p≤0.05) decrease in peak viscosity, final viscosity, setback viscosity, trough viscosity and pasting temperature in dose dependent manner. Swelling, solubility index, oil absorption capacity and water absorption capacity increased significantly with dose, while as syneresis decreased with dose. Gelatinization temperatures To, Tp and Tc decreased significantly with dose. X-ray diffraction showed a characteristic C type pattern of the starches and the crystallinity decreased with dose. Scanning electron microscopy revealed small oval shaped starch granules and slight surface fissures were seen in the irradiated starch treated with 5 and 10kGy.

Primena i ograničenja SEM-EDS metode u tehnologiji hrane i tekstila

Compared to other methods of investigation, the scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) method is significantly less frequently used in the study of the samples related to food and textile technologies. Food scientists most commonly use the SEM-EDS method to investigate the starch morphology of different plants as differences in the size and shape of starch granules may be attributed to the biological origin and physiology of the plant. In addition, these researchers manipulate the starch structure and control the interactions between starch and other food components to determine its effect on the rate of digestion. In textile technology, researchers use the SEM-EDS method to investigate contemporary antimicrobial textiles to assess their possible use in medical equipment as the means to avoid the spread of microbes. SEM-EDS method is often used for the purpose of biodeterioration in the study of historical textiles which have been colonized by microorganisms. However, the inability to analyze wet samples is the main limitation of the SEM-EDS method in the investigation of food samples. This limitation can be partially overcome by studying wet samples under low vacuum conditions, or by creating a non-conventional cross-section of fresh samples which, when covered with a gold layer, can be investigated under high vacuum conditions. Textile samples cannot be polished, which limits the use of this method in obtaining a quantitative chemical analyses. New possibilities of applying the SEM-EDS method in the investigation of food and textile samples should be considered because some limitations of this method can be partially exceeded.

Starch Structure and Physicochemical Properties of Colored Rice Varieties

유색미 가공소재 탐색 및 용도 다양화를 위해 일품을 포함하여 흑미 메벼 6품종, 적미 메벼 3품종, 흑미 찰벼 5품종, 적미 찰벼 1품종으로 일품과 유색미 15개의 품종의 전분 이화학적 구조적 특성을 분석하여 가공용도 다양화를 위한 기초자료로 활용하고자 한다. 1. 유색미의 일반성분을 분석한 결과, 눈큰흑찰이 조단백, 조지방, 식이섬유이 함량이 다른 품종에 비해 높은 경향이었고, 적미의 모든 품종은 조지방이 흑미에 비해 높은 함량을 나타내었다. 2. 유색미 가루를 이용한 찰벼 품종의 아밀로스 함량은 3~5%, 메벼 품종의 아밀로스 함량은 15~18%를 나타내었고, 메벼 품종 중 조은흑미는 14%대로 다소 낮은 함량을 나타내었다. 또한 일품이 80%로 가장 높은 총 전분 함유량을 보였고, 눈큰흑찰과 흑진주가 70, 71%로 가장 낮은 총 전분 함량을 나타내었다. 3. 유색미 가루의 호화특성을 분석한 결과, 모든 유색미의 호화개시온도는 <TEX>$68^{\circ}C$</TEX>였으며, 일품의 호화개시온도인 <TEX>$67.95^{\circ}C$</TEX>와 비슷하였다. 최고점도는 일품이 가장 높았으며, 적진주, 홍진주, 건강홍미 순으로 적미 메벼 품종이 흑미 품종과 적진주 찰에 비해 높은 것으로 나타났다. 치반점도 값으로 본 노화정도 찰벼 품종에서 느린 것으로 확인되었고, 조은흑미는 메벼품종 중에서 노화정도가 느린 것으로 분석되었다. 4. 유색미의 전분외형은 대부분 <TEX>$2{\sim}5{\mu}m$</TEX> 크기의 다각형의 치밀한 입자로 이루어져있으며, 결정성 분석에서는 모두 A type의 전분구조를 이루고 있었지만 결정성은 품종마다 다소 차이를 보였다. 5. 아밀로펙틴의 체인 길이 분석에서는 16개의 품종에서 12<DP<TEX>${\leq}24$</TEX>인 B사슬 함량이 50%이상을 차지하였고, 다음으로 DP<12 함량이 대부분 33~35%함량을 나타내었다. 중합도 36개 이상의 장쇄사슬은 흑미가 적미에 비해 함량이 높은 경향이었다. We investigated the physicochemical properties and starch structure of various rice varieties including 15 colored cultivars. NKHC showed the highest level of protein, lipid, and total dietary fiber levels. Reddish brown rice showed higher lipid content than that in black rice cultivars. Apparent amylose content of waxy and non-waxy colored rice varieties was within the range of 3~5% and 15~18%, respectively. IP exhibited the highest total starch (TS) content, whereas, NKHC and HJJ showed lower TS content than that in other cultivars. Pasting temperature of all colored rice cultivars, except IP, was about <TEX>$68^{\circ}C$</TEX>. Peak viscosity of IP, JJJ, Hong, and GGHM showed high values of 138, 130, 128, and 124, respectively. All the colored rice cultivars presented A-type X-ray diffraction pattern and polygonal shapes of starch granules were observed using scanning electron micrographs (SEM). Major groups of amylopectin chain lengths were B (12 < DP <TEX>${\leq}$</TEX> 24) and A (DP <TEX>${\leq}$</TEX> 12). SMHC showed the highest B chain content and the lowest A chain content (P < 0.05). These experimental results provided useful information for scientists and the food industry regarding colored rice starches.

Heat and moisture modification of native starch granules on susceptibility to amylase hydrolysis

Although annealing and heat-moisture treatments do not gelatinize or modify the size or shape of starch granules, the treatments do cause modification to the internal structure of the granules and as a consequence of these changes, modify the rate and extent of hydrolysis by amylases. This mini-review considers these processes in the context of starch modification and digestion.

Study on Starch Granules of Local Varieties of Dioscorea hispida and Dioscorea alata

Starch is regarded as vital in the food industry, where granule size and shape determine its function and uses. One plant taxon that is widely known as a starch source is Dioscorea (Dioscoreaceae), whose starch and protein content make it a healthy food. As the initial step to identify which varieties possess potential as starch sources, we conducted study on starch granule morphology of some local varieties of D. hispida and D. alata . The aim of this study was to determine shape and size variation of starch granule of each variety of D. hispida and D. alata . The results showed that starch granule morphology does not only vary between species of D. hispida and D. alata , but also among varieties of those species. The shape of starch granules in D. hispida is dominantly polygonal (polyhedral). It showed similar results as those reported by other authors in their studies, except that – in this study - we found there is also a triangular shape, which has never been reported before. Starch granule size of D. hispida is found to be “Very small – Small” and only 1 variety of the species – that is gadung jahe – is classified as “Small” type. According to previous studies, varieties with small type starch granule are recommended as potential sources for non-food industrial raw materials. The shape of starch granules in D. alata is similar to those reported in other studies, which is dominantly triangular and polygonal; the size is classified as “Medium” type, except for two varieties that are uwi ratu and uwi ulo (DC5), which are classified as “Large”. According to previous studies, varieties with large type starch granule are recommended as potential sources for food. Thus, from this study 3 potential local varieties are identified, i.e. gadung jahe of D . hispida , and uwi ratu & uwi ulo of D . alata .

Granule Size and Distribution of Raw and Germinated Oat Starch in Solid State and Ethanol Solution

The morphology and granular properties of oat starch during germination were investigated by scanning electron microscopy and X-ray powder diffractometer. The granule size distribution of oat starch was studied in various concentrations in ethanol using a laser particle-size analyzer. The starch granule shape before germination remained almost the same after germination, as shown by low-magnification (×1000) scanning electron microscopy. However, surface fissures at high-magnification (×5000) were found on the sample at the end of germination. After soaking, the relative crystallinity of the samples significantly reduced, by following increased and then decreased, reaching a maximum crystallinity of 16% at the end of germination. In various ethanol concentrations, the size of starch granules produced in different germination phase slightly varied, but this difference was not easy to detect in the scanning electron microscope ×1000 images. Overall, the particle size of oat starch generally decreased and the specific surface area increased significantly during oat germination.

Pembuatan Dan Evaluasi Pati Talas (Colocasia esculenta Schoot) Termodifikasi dengan Bakteri Asam Laktat (Lactobacillus sp)

Pembuatan dan evaluasi pati talas (Colocasia escuenta Schott) termodifikasi dengan bakteri asam laktat (Lactobacillus sp) telah dilakukan. Tujuan penelitian ini adalah untuk melihat pengaruh modifikasi pati talas dengan bakteri asam laktat terhadap rendemen pati talas dan sifat fisikokimia pati. Evaluasi yang dilakukan meliputi organoleptik, kadar air, pH, sudut angkat, daya pengembangan, temperatur gelatinasi, kadar amilosa, dan pemeriksaan bentuk permukaan granula pati menggunakan SEM (Scanning Electron Microscope). Hasil penelitian menunjukkan rendemen pati talas termodifikasi lebih tinggi (19,24%) daripada pati alami (11,79%). Pemeriksaan organoleptik pati talas termodifikasi menunjukkan hasil yang lebih baik dibandingkan pati talas alami, dimana bau khas talas agak sedikit berkurang dan warnanya lebih putih. Selain itu daya pengembangan dan kadar amilosa pati talas termodifikasi mengalami peningkatan. Hasil lainnya menunjukkan bahwa pada pati talas termodifikasi terdapat perlubangan pada permukaan granulanya.