Amylopectin Ratio Research Articles

Impacts of Cellulose Fiber Particle Size and Starch Type on Expansion During Extrusion Processing.

Objective of this study was to understand the impacts of cellulose fiber with different particle size distributions, and starches with different molecular weights, on the expansion of direct expanded products. Fiber with 3 different particle size distributions (<125, 150 to 250, 300 to 425 μm) and 4 types of starches representing different amylose contents (0%, 23%, 50%, and 70%) were investigated. Feed moisture content (18 ± 0.5 % w.b) and extruder temperature (140 °C) were kept constant and only the extruder screw speed was varied (100, 175, and 250 rpm) to achieve different specific mechanical energy inputs. Fiber particle size and starch type significantly influenced the various product parameters. In general, the smaller fiber particle size resulted in extrudate with higher expansion ratio. Starch with an amylose: amylopectin ratio of 23:77 resulted in highest expansion compared to the other starches, when no fiber was added. Interestingly, starch with 50:50, amylose: amylopectin ratio in combination with smaller fiber particles resulted in product with significantly greater expansion than the control starch extrudates. Aggregation of fiber and shrinkage of surface was observed in the Scanning Electron Microscope images at 10% fiber level. The results suggest the presence of active interactions between the cellulose fiber particles and corn starch molecules during the expansion process. A better understanding of these interactions can help in the development of high fiber extruded products with better expansion.

Effect of steam explosion pre-treatment on molecular structure of sweet potato starch

Purpose: To examine the effect of steam-explosion (SE) strength on the molecular structure of sweet potato starch.Methods: Sweet potato starch was pre-treated using SE method. The effects of SE pressure and pressure-holding time on the molecular structure of the sweet potato starch were investigated by gel chromatography (GPC), infrared spectroscopy, and grading analysis.Results: The molecular weight (MW) of the starch pre-treated by SE technology decreased with increasing explosion pressure and pressure-holding time; however, the individual MW of amylopectin and amylose declined from 439,834 and 6578 to 238,603 and 4845, respectively. Furthermore, the peak area ratio (obtained by GPC) of amylopectin decreased from 84.39 to 65.16 % while that of amylose increased from 15.61 to 34.84 %. No new absorption peaks were found in the infrared spectra of sweet potato starch following SE pre-treatment. Crystallization index and median diameter of sweet potato starch increased from 1.661 to 1.959 and from 13.73 μm to 76.36 μm, respectively, with rising pressure and pressure-holding time, following SE pre-treatment.Conclusion: SE pre-treatment effectively degrades the degree of polymerisation of molecular chains in sweet potato starch and enhances the degree of crystallinity thereof. SE method is an approach for the production of sweet potato starch with high-level anti-digestion characteristics.Keywords: Sweet potato starch, Steam-explosion, Molecular weight, Degree of crystallinity, Particle diameter

Fluorescence-labelling for analysis of protein in starch using asymmetrical flow field-flow fractionation (AF4)

Starch is a mixture of amylose (AMY) and amylopectin (AMP) which are different in physical properties such as molar mass (M), rms radius (R g ) and hydrodynamic diameter (d H ). The rheological and functional properties of starch are influenced by various factors including the molecular size, molar mass distribution (MD) and the concentration ratio of AMY and AMP. It is also important to analyze proteinaceous material in starch as they affect the flavor and texture of food to which starch is added. In this study, asymmetrical flow field-flow fractionation (AF4) was employed for separation and quantitation of AMY and AMP in starches (Amaranth, potato, taros and quinoa). AF4 was coupled with a multi-angle light scattering (MALS) and a refractive index (RI) detector for determination of the absolute M, MD and molecular structure. It was found that AMP has the M and R g ranging 3.7 × 10 7 ~ 6.5 × 10 8 g/mol and 84 ~ 250 nm, respectively. Also the existence of branch was confirmed in higher M. In addition, proteinaceous material in starch was analyzed by AF4 coupled with a fluorescence detector (FS) after fluorescence-labeling. AF4-FS with fluorescence-labelling showed a potential for investigation on existence of proteinaceous material and the interaction between proteinaceous material and polysaccharide in starch.

Glycaemic and Insulin Response to Equi-Quantity of Selected Common Indian Staples in Individuals with Type 2 Diabetes Mellitus.

Diet therapy is one of the corner stone's in the management of diabetes. Keeping the blood sugar level as close to normal is the main focus of dietary management of diabetes. A typical Indian meal is largely composed of Carbohydrates (CHO). Consumption of staple cereals, forms the major source of CHO in the Indian diet. However, CHO metabolism is seen to be completely deranged in a person with type 2 diabetes. It is necessary to select the cereal which has lower postprandial glycaemic impact for subjects with compromised metabolic status. Preference between two main staple cereals rice and wheat as staple food, especially for diabetic group, will depend on the equi-quantity based postprandial glycaemic impact of these cereals. To identify the cereals, better suited for individuals with diabetes (based on postprandial glycaemic and insulinemic impact of rice and whole wheat Indian flat bread i.e., chapatti). After an overnight fast and upto 2 hours for every half an hour, finger tip blood samples for fasting and postprandial blood sugar was assessed. Venous blood for estimation of insulin levels were also collected from enrolled diabetic individuals and paired normal subjects. About 50 gm of test food like boiled rice, whole wheat chapatti and white bread as standard food were given on different occasions. Glucose and insulin levels were measured using glucometer and ECLIA method. Contrary to the popular belief, it was seen that rice exerted a lower peak and lower postprandial glycaemic and insulinemic response in both the study groups. Factors such as co-nutrient, moisture and fiber content all exert an impact on the postprandial glucose and insulin levels. With this the grain structure, particle size and amylose: amylopectin ratio are also important determinants. When foods are considered as a whole and not a single nutrient, rice proves to be a better product for effective management of blood sugars in individuals with type 2 diabetes mellitus.

Influence of germination conditions on malting potential of low and normal amylose paddy and changes in enzymatic activity and physico chemical properties

Malting potential of two rice cultivar i.e. low (12.5%) (LR) and normal (20.2%) amylose paddy (NR) were evaluated under different germination conditions (25-40°C for 120h). Based on malting potential, 30 and 35°C germination temperatures were found suitable. Enzymes (amylolytic and α-amylase) activity increased at both temperatures for LR and NR whereas NR exhibited higher activity. NR malted rice showed higher starch degradation (64 and 74 times) when compared to LR (58 and 62 times) at 30 and 35°C respectively leading to formation of reducing sugar and lowering of viscosity. During germination of LR and NR significant morphological and structural changes were observed as evident from pin-holes and eroded surface in micrographs, decreased % crystallinity and FTIR peaks. Outcome of present study concluded that the amylose amylopectin ratio played an important role during germination and NR paddy was found more suitable for malting at 30 and 35°C.

Influence of the starch structure in the synthesis and the yield of levulinic acid

Starch is a promising feedstock for the synthesis of chemical intermediates like levulinic acid (LA), but the role played by the amylose–amylopectin ratio of starch in LA yields has not been investigated so far. In this work, corn starch was fractionated using the aqueous leaching–alcohol precipitation method, and the morphological and thermal degradation characteristics of the amylose and amylopectin obtained were studied. A comparison of the results of acid-catalysed hydrolysis of the original starch and the fractions showed that differences in granule size, solubility, and susceptibility to acid hydrolysis are the main factors affecting LA yields. Amylopectin yielded LA at faster rates at 150 and 165°C than amylose, which is a factor that may influence the selection of starches for the production of LA at an industrial scale.

Physicochemical, morphological, thermal and pasting properties of marama (Tylosema esculentum) storage root starch

Starch from marama (Tylosema esculentum) storage roots were isolated and characterized for physicochemical, micro‐ and molecular structure, pasting, and thermal properties, and were compared to commercial cassava, maize, and potato starches. The amylose content of marama root starch was 192 g/kg starch; and was close to cassava (196 g/kg), but lower in comparison to maize (250 g/kg) and higher than potato (161 g/kg). Marama root starch granules were found to be simple; spherical, lenticular, and oval in shape with granule size range of about 5–38 µm. The peak viscosity (5350–5475 mPa · s) of marama root starch paste is about twice as high as those of cassava and maize. Marama root starch has higher gel firmness than cassava but half that of potato and maize starches. Gelatinization temperature range (67.5–79.0°C) of marama root starch was close to commercial cassava and maize starches. Marama root starch exhibited type A molecular arrangement (X‐ray diffraction) pattern similar to the cassava and maize starches, but different to type B exhibited by the potato starch. Granule size, amylose:amylopectin ratio and molecular arrangement pattern seem to account for the differences and or similarities between marama root starch and the commercial starches. Marama starch has potential as thickeners in food compared to maize and cassava due to the high viscosity.

Gastrointestinal tract development in fattening lambs fed diets with different amylose to amylopectin ratios

Thirty-six, 7-d-old male lambs of similar weights were used in the current study to examine the effects of dietary amylose to amylopectin ratios (amylose/amylopectin) on gastrointestinal development in fattening lambs fed concentrates with different sources of starch (tapioca, wheat, maize, and pea) and amylose/amylopectin (0.12, 0.23, 0.24, and 0.48, respectively). The maize starch (MS) and wheat starch (WS) diets improved weight and volume of gastrointestinal. The pea starch diet significantly increased papillar height (P &lt; 0.001), papillar surface area (P = 0.019), and density of papillae (P = 0.001) in the rumen. Additionally, the pea starch diet significantly enhanced villus height, crypt depth, and villus surface area and villus/crypt ratio (P &lt; 0.05) in small intestine. Expressions of insulin-like growth factors I (IGF-1) and insulin-like growth factors’ receptors (IGF-1R) significantly increased in the duodenum mucosa (P = 0.021, P = 0.006, respectively), jejunum mucosa (P = 0.002, P = 0.005, respectively), and ileum mucosa (P = 0.003, P &lt; 0.01, respectively) in the pea starch diet group. The results of the present study show that MS and WS accelerated physical development of rumen and intestine compartments, whereas pea starch increased development of their some morphological parameters, possibly through enhanced expression of genes such as IGF-1 and IGF-1R in fattening lambs.

Effect of low-pressure plasma on physico–chemical and functional properties of parboiled rice flour

The present research was conducted to study the efficacy of low pressure plasma treatment in modification of parboiled rice flour. Parboiled rice samples were taken and plasma treated at varying power of 30 W, 40 W and 50 W for duration of 5, 10 and 15 min. After treatment, the parboiled rice was ground for examining physico–chemical and functional properties of the flour. From the analysis, it was found that plasma treatment could improve the flour hydration and gel hydration properties of the flour. Plasma treatment induced cross-linking of flour. On the contrary, the plasma treatment reduced the amylose content from 30.34 ± 0.13 to 27.89 ± 0.09%, which in turn caused a decline in the amylose to amylopectin ratio. This observed result could be due to depolymerization of starch, which is proved to happen during plasma treatment. Other changes that were observed after treatment are increase in gelatinization temperature. Plasma induced changes resulted, decline in endothermic enthalpies from 7.90 ± 0.21 to 7.47 ± 0.21 and changes in % crystallinity of flour from 28.25 ± 0.07 to 24.36 ± 0.48. Further, the phenolic content and antioxidant properties of treated flour samples were also influenced after treatment. It can be concluded that cold plasma treatment can be promising technology for improving functionality of flour.

Effects of corn type and fasting time before slaughter on growth and plasma index in weaning pigs.

A 2 × 2 factorial experiment was conducted to evaluate the effects of dietary corn type (waxy corn [WC] vs. nonwaxy corn [NC]) and fasting period (2 h vs. 12-16 h) before slaughter on growth and plasma index in weaning pigs. Twenty-four crossbred barrows (8.26 ± 0.47 kg) were allotted to 4 treatments with 6 replications of 1 pig per replicate metabolism cage. Waxy corn contained less fat, a lower amylase:amylopectin ratio, more CP, and more starch than NC. Pigs fed the WC diet had lower jejunum digesta pH compared with those fed the NC diet ( < 0.05). Maltase activity in the jejunum and ileum mucosa ( < 0.01), sucrose activity in the ileum mucosa ( < 0.01), and amylase activity in the pancreas and jejunum digesta ( < 0.05) were increased in pigs fed the WC diet relative to those fed the NC diet. But the total tract apparent digestibility (TTAD) of starch and CP was lower for the WC group ( < 0.05). Ingestion of the NC diet resulted in higher ( < 0.05) ADG and ADFI in the second week but did not affect ADG ( = 0.091) and the feed:gain ratio (F:G; = 0.077) during the whole experiment period. The plasma glucose ( < 0.01) concentration was higher and high-density lipoprotein cholesterol (HDL-C; < 0.01) concentrations was lower in the hepatic portal vein in pigs fed the WC diet relative to those fed the NC diet. Fasting 2 h before slaughter decreased the jejunum and ileum digesta pH compared with the 12-h fasting group ( < 0.01). Villus height increased in the duodenum ( < 0.01) and jejunum ( < 0.05) and the villus height:crypt depth ratio increased in the duodenum ( < 0.05) of pigs after shortening the fasting period before slaughter. Shortening the fasting time before slaughter resulted in higher plasma glucose ( < 0.05) concentrations and a higher HDL-C:low-density lipoprotein cholesterol (LDL-C) ratio ( < 0.05) whereas the LDL-C ( < 0.05) concentrations were reduced in the hepatic portal vein. The results of this experiment indicate that although the production performance of both WC and NC diets is equal, the glucose concentration is higher and HDL-C is lower in the portal vein for the WC diet, and fasting time before slaughter has an influence on the plasma index and intestinal morphology in weaning pigs.

Soaking Induced Changes in Chemical Composition, Glycemic Index and Starch Characteristics of Basmati Rice

An attempt was made to determine the qualitative changes in basmati rice (Pusa Basmati 1121, PB1121) during soaking at 40°C to 80°C. Soaking temperature had significant effect (α = 0.01) on chemical composition, glycemic index and starch characteristics of rice. Starch content, apparent amylose content, crude protein content and crude fat content in un-soaked rice were found to be 73.24%, 27.26%, 8.79% and 2.56%, respectively, but differences in these traits were observed after soaking. Amylose to amylopectin ratio (Am/Ap) decreased from 0.59 to 0.52 (soaked at 80°C). Crude fibre and crude ash contents increased after soaking. The mineral composition (K, P, S, Ca, Mg, Mn, Fe, Cu and Zn) in soaked rice was found to be 16.46% higher than un-soaked rice at the same degree of polishing. Glycemic index of un-soaked rice was found to be 58.41, but decreased to 54.31 after soaking at 80°C. Pasting properties, scanning electron microscope images, and X-ray diffractograms suggested partial gelatinization of starch in the temperature range of 60°C to 80°C. Based on qualitative changes in rice (apparent amylose content, Am/Ap ratio and crystallinity rate), it was concluded that intermediate soaking temperatures (60°C to 70°C) would be useful for soaking of PB1121.

A systematic review of the influence of rice characteristics and processing methods on postprandial glycaemic and insulinaemic responses.

Rice is an important staple food for more than half of the world's population. Especially in Asian countries, rice is a major contributor to dietary glycaemic load (GL). Sustained consumption of higher-GL diets has been implicated in the development of chronic diseases such as type 2 diabetes mellitus. Given that a reduction in postprandial glycaemic and insulinaemic responses is generally seen as a beneficial dietary change, it is useful to determine the variation in the range of postprandial glucose (PPG) and insulin (PPI) responses to rice and the primary intrinsic and processing factors known to affect such responses. Therefore, we identified relevant original research articles on glycaemic response to rice through a systematic search of the literature in Scopus, Medline and SciFinder databases up to July 2014. Based on a glucose reference value of 100, the observed glycaemic index values for rice varieties ranged from 48 to 93, while the insulinaemic index ranged from 39 to 95. There are three main factors that appear to explain most of the variation in glycaemic and insulinaemic responses to rice: (1) inherent starch characteristics (amylose:amylopectin ratio and rice cultivar); (2) post-harvest processing (particularly parboiling); (3) consumer processing (cooking, storage and reheating). The milling process shows a clear effect when compared at identical cooking times, with brown rice always producing a lower PPG and PPI response than white rice. However, at longer cooking times normally used for the preparation of brown rice, smaller and inconsistent differences are observed between brown and white rice.

In vitro and in vivo digestibility of corn starch for weaned pigs: Effects of amylose:amylopectin ratio, extrusion, storage duration, and enzyme supplementation.

The objective of this study was to investigate the effects of amylose (AM):amylopectin (AP) ratio, extrusion, storage duration, and enzyme supplementation on starch digestibility of corn. Three corn varieties with high (0.60; HA), medium (0.44; MA), and low (0.39; LA) AM:AP ratios, respectively, were selected from 74 corn samples to evaluate the in vitro and in vivo digestibility of starch. In Exp. 1, during wk 4 after extrusion, resistant starch (RS) content of the 3 selected corn varieties (LA, MA, and HA) increased (P < 0.05) each week and starch digestibility in vitro decreased as storage time increased (P < 0.05). The AM:AP ratio affected the formation of RS (P < 0.01). The RS content of the 3 corn varieties was ranked as LA < MA < HA in each week (P < 0.05). Correlation analysis showed that AM:AP ratio and storage duration were both positively correlated with RS content (P < 0.01). Furthermore, a significant quadratic relation was found between storage duration and RS content in each corn variety as well as storage duration and digestibility. Starch digestibility was negatively correlated with RS content (P < 0.001). In Exp. 2, digestion trials were performed on cannulated pigs with BW of 13.20 ± 0.94 kg. Extrusion increased ileal digestibility of GE and starch of either HA or LA compared with the enzyme-supplemented diets (P < 0.001). Enzyme supplementation did not improve ileal energy and starch digestibility. The ileal digestibility of starch and GE of LA varieties was greater than HA samples (P < 0.05). The results implied that AM:AP ratio and storage duration after extrusion may be important determinants of RS formation and digestibility of starch for corn. In addition, RS content could be an important indicator of digestibility of starch in extruded corn. Using a lower AM:AP ratio corn or reducing the storage duration of extruded corn would help to reduce the formation of RS and improve the starch bioavailability of corn for piglets.

PATI RESISTEN SAGU HASIL PROSES HIDROLISIS ASAM DAN AUTOCLAVING-COOLING

The aim of this study was to produce resistant starch (RS) from a combination of acid hydrolysis and autoclaving-cooling processes of sago starch. This study compared two methods of starch modification to produce RS, i.e. (1) acid hydrolysis treatment followed by autoclaving-cooling cycles (AH-AC), and (2) autoclaving-cooling cycles followed by acid hydrolysis treatment (AC-AH). The acid hydrolysis used 1 and 2% HCl while autoclaving-cooling process consisted of three-cycle of autoclaving at 121°C for 30 min followed by cooling at 4°C for 72 hrs. Both AH-AC and AC-AH modification methods decreased starch content, altered amylose and amylopectin ratio, and increased RS contents. Both modification methods also yielded nearly flat pasting profiles at both heating and cooling phases as compared to that of native sago starch. At the same HCl concentration, the AH-AC process yielded a higher RS content than that of AC-AH. Among all treatments, the acid hydrolysis treatment using 1% HCl followed by three cycles of autoclaving-cooling process yielded the highest RS content (74.28%). The crystallinity of RS was also lower than of native sago starch, but its A crystalline type remained the same.

Effects of different amylose to amylopectin ratios on serum indices related to glucose metabolism and glucose transporter expression in fattening lambs

The objective of this study was to determine the effects of different amylose to amylopectin ratios on serum indices related to glucose metabolism and the mRNA expression of glucose transporters in the small intestinal mucosa of fattening lambs. A total of 36 male 7-day-old lambs of similar weight were randomly assigned to four treatments of iso-starch diets containing tapioca starch, maize starch, wheat starch, and pea starch, with the determined ratio for amylose to amylopectin of 0.12, 0.23, 0.24, and 0.48, respectively. Serum glucose, creatinine, insulin, and glucagon were reduced with the advancing age of lambs. The results indicated that feeding lambs with a pea starch diet (high amylose to amylopectin ratio) had increased serum cholesterol (P=0.047), lactate dehydrogenase (LDH) (P=0.010), and growth hormone (GH) (P=0.037). Pea starch did not influence the serum glucose (P=0.160), but significantly decreased the serum insulin (P=0.021). The pea starch diet significantly up-regulated the mRNA expression of glucose transporters, which may increase intestinal glucose uptake. By contrast, the consumption of tapioca starch resulted in the opposite effects, and significantly down-regulated the mRNA expression of glucose transporters. Collectively, these data suggest that starches with higher amylose to amylopectin ratios promote higher concentrations of plasma cholesterol, LDH and GH, and up regulate the gene expression profile of glucose transporters in fattening lambs.

In Vitro Synthesis of Ten Starches by Potato Starch-Synthase and Starch- Branching-Enzyme Giving Different Ratios of Amylopectin and Amylose

The objectives of this study was the use of two highly purified enzymes, potato Starch-Synthase (SS) and Starch- Branching-Enzyme (SBE) to obtain in vitro the syntheses of ten starches, with different ratios of amylopectin and amylose. The amylose was first synthesized by the reaction of SS with ADP [14C] Glc to give ten identical amyloses; the amylopectin was then synthesized by the action of SBE to give ten starches with different amounts of amylopectin. Two of the 14C-amyloses were reacted with 1.0 mIU of purified Starch-Branching-Enzyme (SBE) for 75 and 130 sec, respectively. In a second synthesis, 3 of the amyloses were autoclaved and reacted with 1.0 mIU for 15, 45, and 75 sec. In the third synthesis, 5 amyloses were reacted with different amounts of SBE from 0.50 to 0.01 mIU for 130 sec each. The 10 synthesized starches were separated into amylopectin and amylose fractions. The amylopectin and amylose ratios ranged from 99.9% amylopectin and 0.1% amylose to 10% amylopectin and 90% amylose. The results show that 10 different starches were synthesized, using only two enzymes, SS and SBE. No primers were involved. Glycogen and debranching enzymes were also not involved.

Effect of amylose:amylopectin ratio and rice bran addition on starch films properties

The influence of the amylose:amylopectin ratio on the properties of pea, potato and cassava starch films and the effect of the incorporation of rice bran of two different particle sizes were studied. The structural, mechanical, optical and barrier properties of the films were analyzed after 1 and 5 weeks. The high content of amylose gave rise to stiffer, more resistant to fracture, but less stretchable films, with lower oxygen permeability and greater water binding capacity. Although no changes in the water vapour permeability values of the films were observed during storage, their oxygen permeability decreased. Throughout storage, films became stiffer, more resistant to break, but less stretchable. Rice bran with the smallest particles improved the elastic modulus of the films, especially in high amylose content films, but reduced the film stretchability and its barrier properties, due to the enhancement of the water binding capacity and the introduction of discontinuities.

Comparative binding and disintegrating property of Echinochloa colona starch (difra starch) against maize, sorghum, and cassava starch

Context: Starch obtained from different botanical sources exhibit different characteristics due to variation in amylase–amylopectin ratio, which results in different binder substrate interactions.Objective: The present study characterized Echinochloa colona (L.) Link (Poaceae) starch and evaluated its compressional characteristics for use as tablet excipient against commonly used maize, sorghum, and cassava starch.Materials and methods: Three experimental design studies were performed to determine the effects of the maize starch and povidone on physical properties of paracetamol (250 mg) tablets. The effect of superdisintegrants sodium starch glycolate and croscarmellose sodium on the optimized composition obtained in the preceding experiments was evaluated in two factorial experimental studies. The maize starch in the optimum formulations was replaced with difra, sorghum, and cassava starch, and tablets prepared from these starches were compared for their compressional characteristics, lubrication sensitivity, moisture uptake, and drug release.Results: Tablets prepared from maize starch and povidone (30:9, w/w) blend which was previously mixed for 8 min disintegrated (DT) in 10 min. Superdisintegrants decreased DT of tablets significantly (p < 0.05) to 2.2 min. The Hausner ratios of co-processed mixtures containing sorghum, maize, and difra starch were 1.19, 1.21, and 1.26, respectively, with equilibrium moisture content of 8–9%. The DT of sorghum and difra starch formulations which related directly to their higher hydration capacity (difra > sorghum > maize starch) and swelling property was 1.5 min and 2.5 min, respectively, with a friability of 0.32%. The effect of lubrication on the DT and friability of tablets containing maize and difra starch was significant (p < 0.05). However, more than 90% drug was released in vitro dissolution studies.Conclusion: Difra starch can replace maize and sorghum starch as tablet excipient.

Effects of the amylose–amylopectin ratio on starch–hydrocolloid interactions

Combinations of 4 rice starches with amylose (AM) contents of 0%, 15%, 22%, and 28% and 8 hydrocolloids (xanthan, guar gum, CMC, sodium alginate, HPMC, κ-, ι-, λ-carrageenan) were used (4.75% starch and 0.25% hydrocolloid). With a few exceptions, addition of a hydrocolloid increased peak and final η, breakdown, setback, G″, and η*, K, and ηa,100 values. It is concluded that the AM content of the starch was a greater determinant of pasting, paste, and gel properties than was the added hydrocolloid at the 19:1 (w/w) starch–hydrocolloid ratio used. Reinforced is the previous conclusion that the properties of a starch–hydrocolloid combination are determined by the specific combination.

TEPUNG KAYA PROTEIN DARI KORO KOMAK SEBAGAI BAHAN PANGAN FUNGSIONAL BERINDEKS GLISEMIK RENDAH [Protein Rich Flour from Hyacinth Bean as Functional Food Ingredient with Low Glycemic Index

ABSTRACT Protein-rich flour (PRF) produced from Hyacinth bean (Lablab purpureus (L) Sweet) shows good potency as a functional food ingredient. The PRF was extracted from hyacinth bean using water followed by protein precipitation at its isoelectric point. The precipitate was neutralized using 1 N NaOH and the slurry was dried, ground and sieved. The objective of this research was to characterize the nutritive value of PRF i.e., protein content and amino acid profile, trypsin inhibitors activity, content of vitamins B1 and B2, the amylose and amylopectin ratio of starch and its glycemic index. The results showed that the PRF contained high protein (58.4±4.5%). The major amino acid was glutamic acid, while methionine was found as the limited amino acid of the PRF. The activity of trypsin inhibitor was low (20.4±1.6 unit/g). Moreover, PRF contains 0.2 and 3.6 mg/100 g of vitamins B1 and B2 respectively. With a high ratio of amylose (30.0±2.0%) and high content of resistance starch (7.97 g/100 g), the PRF showed a low glycemic index (43.50). Based on its characteristics, this PRF can be promoted as a new food ingredient, especially for diabetic diet. Keywords: glycemic index, nutritive value, protein rich flour Komak (Lablab purpureus (L) Sweet)