Full Text Available The mixolab, a rheological device developed recently, combines approved farinograph and amylograph test procedures. Analysing wheat flour composites with hemp, teff, or chia in terms of all three mentioned rheological methods, correspondence of farinograph, and amylograph versus mixolab features was examined by principal component analysis. The first two principal components, PC1 and PC2, explained 75% of data scatter and allowed a satisfying confirmation of presumed relationships between farinograph or amylograph and mixolab parameters. Dough development time and stability were associated with gluten strength (C1 torque point and also dough softening (mixing tolerance index had a link to protein weakening (C1-C2 difference. In the second mentioned case, amylograph viscosity maximum and amylase activity (C3-C4 closeness was verified. Starch and starch gel properties during mixing (C3, C3-C2, and C4 affect dough viscosity (C1 and rheological behaviour (dough development time and stability. Another important finding is unequivocal distinguishing of the composite subsets (of hemp, teff, and chia ones by the used rheological methods and statistical treatment of multivariable data.
Raden Haryo Bimo Setiarto
Full Text Available Tacca (Tacca leontopetaloides is plant that grows in coastal areas and high salinity, especially in the south coast of West Java. Tacca tubers have high content of carbohydrate, but it also contains some toxic compounds such as: taccaline, β – sitosterol, alcohol cerylic, and steroid sapogenin that are harmful for health. Fermentation on tacca tubers can change amylograph properties and proximate levels of modified tacca flour and reduce it toxic compounds. This study aimed at determining the effects of lactic acid bacteria (LAB Lactobacillus plantarum B307 fermentation on the proximate levels and amylograph characteristics of modified tacca flour. Moisture and ash content of modified tacca flour still meet the requirements of SNI. Fermentation LAB Lactobacillus plantarum B307 led to increased levels of protein and lactic acid in the modified tacca flour, but it decreased pH value and carbohydrate content. Based on the analysis of amylograph, it can be concluded that tacca flour control without fermentation has the best gelatinization profile because it has good ability of setback viscosity.
Full Text Available The paper presents the results of the evaluation of the effect of additives on the rheological properties of composite flour made of wheat flour in the amount of 70% and spelt flour at 30%. As additives guar gum (0.5% by weight of flour and xanthan gum (0.16% by weight of flour were used. Properties of produced control dough and doughs with hydrocolloids were evaluated by means of rheological appliances by Farinograph, Extenzograph, Amylograph and Rheofermentometer. Based on the observed results it can be concluded that the addition of xanthan gum has a positive effect on increasing of farinographic water absorption capacity, extension of dough development time and dough stability and generally positively affected farinographic properties. The addition of guar gum has improved especially extensographic properties as extensographic energy and extensographic resistance. Based on amylographic evaluation of control doughs and doughs with additives it can be stated that in the dough with guar gum the amylographic maximum has slightly increased. Hydrocolloid guar gum contributed to an increased retention capacity of dough observed. Based on our measurements we can indicate that addition of guar and xanthan gum contributed to an increased rheological quality of doughs prepared with addition of flour from spelt wheat. With reference to the baking experiment it was found that the use of hydrocolloids has a positive effect on the improvement of the baking properties, in particular larger volume, specific volume, and the volume yield of the dough with the addition of guar and xanthan gum compared to the control. Our results showed that aditives significantly influenced rheological qualities of dough and a baking quality of products. These findings thus allow optimizing the recipe in order to increase the technological quality of leavened bakery products.
Lares, Mary; Pérez, Elevina
The goal of this study was to evaluate the effect of the physical modification by microwave irradiation on the mineral fraction and rheological properties of starch isolated from Canna edulis rhizomes. Phosphorus, sodium, potassium, magnesium, iron, calcium and zinc were evaluated using atomic absorption spectrophotometry. Rheological properties were determined using both the Brabender amylograph and Brookfield viscosimeter. Except for the calcium concentration, mineral contents decreased significantly (p canna starch may be modified by microwave irradiation in order to change its functional properties. This information should be considered when using microwave irradiation for food processing. Furthermore, the altered functional attributes of canna modified starch could be advantageous in new product development.
Hansen, Hanne B; Møller, Birthe; Andersen, Sven B; Jørgensen, Johannes R; Hansen, Ase
Grain characteristic, chemical composition, and functional properties of rye were measured in 19 different cultivars grown in one location in up to 3 years. The cultivars included 8 adapted hybrids, 7 adapted population cultivars, and 4 nonadapted population cultivars. The results showed a significant influence of both harvest year and genotype on grain characteristics, chemical composition, and functional properties of the grain. Multivariate data analysis confirmed that the variations in the data were explained by yearly and genotype differences. Calculations of variance components showed that the variations in plant height, harvest yield, and protein content were mainly due to genotype differences and to a lesser extent to differences among harvest years. The kernel weight, hardness index, and content of dietary fiber components, however, were more strongly influenced by the harvest year than by the genotype. Differences in starch properties measured by falling number (FN), amylograph peak viscosity, and temperature at peak viscosity were more strongly influenced by harvest year. The water absorption was strongly influenced by genotype effects, compared to yearly differences. FN and amylograph peak temperature were positively correlated (r = 0.94). No correlation was found between the water absorption and the relative proportion of water-extractable arabinoxylan (AX) compared to the total AX content. However, the degree of ferulic acid cross-linking showed a negative correlation (r = -0.70) with the water absorption.
H. G. Kotancilar
Full Text Available The starches of wheat and corn treated with four different modification methods (pregelatinized, thinnedwith acid, cross-linked and dextrinized were investigated in terms of changes in swelling, water-holdingcapacity, gelatinization and thermoanalytical properties. Modification processes caused significant changes inthe physicochemical properties of the starches. Also, having effect on the thermoanalytical properties ofstarch, of modification process pregelatinization, cross-linking and dextrinization increased the temperaturesof gelatinization initiation, peak, and final points. In addition, the modification process decreased the changein the value of entalphi. In general, peaks appeared in shorter time in corn starch amylograph than that inwheat starch for all the modified methods. The wheat starch had more swelling capacity than those of thecorn starch at 30 and 40 oC. The modifications applied, in this study, decreased water-holding capacity of thestarches of the wheat and corn at 70 oC.
Madhusudhan, B.; Susheelamma, N.S.; Tharanathan, R.N. (Central Food Technological Research Inst., Mysore (India). Dept. of Food Chemistry)
By differntial sedimentation and centrifugation steps four starch isolates were recovered from sun dried sweet potato flour. The granules in these isolates were of different size, shape and population characteristics, and were anionic in nature. They showed a single stage swelling with 30 to 35% solubility in water and only [proportional to]30% solubility in DMSO even after 72 h. Their starch content varied from [proportional to]48 to 88%. The presence of thermostable amylases in sweet potato resulted in considerable decrease in Brabender viscosity values as amylographic studies in the presence of HgCl[sub 2] showed significant increase in peak (PV) and setback (SBV) viscosities. The starch isolate I had 25% higher PV as compared to the isolate II but retrogradation was much low in this. Susceptibility to glucoamylase digestion showed a decreasing trend from the isolate I to the IV on solid basis, but comparable on starch basis. (orig.).
Srivastava, Prateeti; Indrani, D; Singh, R P
Pomegranate (Punica granatum) peel is rich source of dietary fiber and bioactive compounds, hence could be used in the development of functional food formulations. Attempt was made to see the effect of dried pomegranate peel powder (DPPP) and emulsifiers on the rheological, nutritional and quality characteristics of biscuits. Incorporation of DPPP from 0 to 10% increased farinograph water absorption, decreased dough stability, increased amylograph pasting temperature and peak viscosity of wheat flour; increased hardness and decreased cohesiveness of biscuit dough; decreased spread ratio and increased breaking strength of biscuits. Sensory evaluation showed that biscuits incorporated with 7.5% DPPP were acceptable. Among emulsifiers, sodium stearoyl lactylate significantly improved the quality characteristics of 7.5% DPPP incorporated biscuits. Addition of 7.5% DPPP increased the protein, dietary fibre, minerals, anti-oxidant activity and β-carotene contents of biscuits. The studies indicated the possibility of utilizing DPPP to improve the nutritional characteristics of biscuits.
Mirić Katarina V.
Full Text Available This work in concerned with the interdependence between technological quality of mill stream flours and fermentative activity of baker's yeast Saccharomyces cerevisiae. Each mill stream flour has its own specific properties, determined by the particle size, technological phase of its formation and part of the wheat kernel it consists of. Biochemical complexity of dough during examination of fermentative activity of baker's yeast confirmed the influence of a number of physical and biochemical flour properties, such as ash content, wet gluten content, rheological flour properties, phytic acid content and amylograph peak viscosity. Abudance of significant flour characteristic, their interaction and different behavior in the presence of the yeast, showed diversity and variation of result within the same category of the mill stream flour.
Ogunsina, B S; Radha, C; Indrani, D
The effects of replacing wheat flour with 0-15% debittered moringa seed (DBMS) flour on the dough rheology of wheat flour and physical, sensory and chemical properties of bread were studied. Incorporation of an increasing amount of DBMS from 0 to 15% decreased farinograph water absorption, dough stability, amylograph peak viscosity and overall quality of bread. The bread with 10% DBMS had a typical moringa seed taste and was acceptable. Addition of combination of additives improved the dough strength and quality of bread with 10% DBMS flour. Replacement of wheat flour with 10%, 20% and 30% DBMS grits was found to affect cookies quality. Cookies with 20% DBMS grits had the nutty taste of moringa seeds and were acceptable. Bread with 10% DBMS flour and cookies with 20% DBMS grits had more protein, iron and calcium. Incorporating moringa seeds in baked foods may be exploited as a means of boosting nutrition in Africa and Asia where malnutrition is prevalent.
Rawat, Neelam; Darappa, Indrani
Effect of substitution of brown flour (BF) with fiber rich ingredient mixture, FRIM (banana flour, psyllium husk, partially defatted coconut flour and oats) and protein rich ingredient mixture, PRIM (chickpea flour, sesame, soya protein isolate and whey protein concentrate) at the levels of 25, 50 and 75 % on the rheological, nutritional and quality characteristics of baked energy bars (BEB) were studied. Use of increasing amount of FRIM increased farinograph water absorption and amylograph peak viscosity while PRIM decreased the aforementioned parameters. Addition of FRIM or PRIM increased the bar dough hardness and decreased cohesiveness and springiness. The overall quality score of BEB increased only up to the substitution of 50 % of BF with FRIM or PRIM. The BEB with 50 % FRIM and PRIM remained chemically stable during storage up to 3 months and showed 9 times increase in dietary fiber content and about 2 times increase in protein content respectively.
Mahvish Jabeen Channa
Full Text Available This study was designed to investigate the physico-chemical and rheological properties of 17 wheat varieties (TJ-83, Jouhar, TD-1, Anmool, Mehran, Indus-66, Sindh B-1, Abadgar, Bhittai, Imdad, Mexi-Pak, Soughat, Blue Silver, Moomal, Marvi, Kiran, and Pak-70 commercially grown on experimental field of Agriculture Research Institute, Tandojam. The results revealed that moisture % were in range of 11 to 12 among all varieties, high protein content of about 15.2% was found in Mehran and Blue silver varieties, starch was found high in Maxi-pak (70.6%, high hardness values in Imdad (70.1% and Jouhar (70.2%. However, zeleny content was found high in Marvi, Abadgaar and Mehran i.e. 71%. Amylographic results showed that among all varieties the Bhittai variety required maximum temperature up to 65.7 oC for the beginning of gelatinization as compared to other varieties. The highest gelatinization temperature was noted up to 96.7 oC in Moomal whereas others had temperature from 82.7 to 89.0 oC. Highest gelatinization maxima (1782AU acquired by T.J-83 variety. The results of Farinograph showed that highest water absorption was noted in Anmool variety. The highest dough development time and dough stability were found highest in Kiran and Indus-66, respectively. T.D-1 and Jouhar varieties had highest break down time as well as highest Farinograph quality.
Abstract: Changes in the milling quality, chemical characteristics, eating qualityand dynamic viscoelasticities of seven cultivars of japoinica rice after about eightmonths storage at room temperature were studied. Comparisons between new andstored rices showed that no obvious changes in milling quality, amylose and proteincontent were found. Though there was varietal difference, the palatability of allcultivars deteriorated with storage.The overall eating quality of Koshihikari andEtsunan162 stored rice were almost the same as that of new rice of Nihonbare andXiushui11. The deterioration in palatability was due to the deterioration of theappearance, taste and stickiness of cooked rice. New rice grain from cultivars witha good eating quality showed a relatively high palatability as compare with storedrice. The moduli of cooked rice grains of stored rice were increased and values ofloss tangent of cooked rice was lower than those of new rice, such cases in poorpalatability cultivars were much more obvious. The eating quality of stored rice wasgenerally poor for the cultivars with a high free fatty acid content. In addition, thebreakdown and maximum viscosity values in amylographic characteristics wereslightly increased.
Yan Wenchao; Jin Qingsheng; Yu Faming; Qiu Boqin; Kastsura Tomita; Hisamitsu Horiuch
Changes in the milling quality, chemical characteristics, eating quality and dynamic viscoelasticities of seven cultivars of japoinica rice after about eight months storage at room temperature were studied. Comparisons between new and stored rices showed that no obvious changes in milling quality, amylose and protein content were found. Though there was varietal difference, the palatability of all cultivars deteriorated with storage.The overall eating quality of Koshihikari and Etsunan162 stored rice were almost the same as that of new rice of Nihonbare and Xiushui11. The deterioration in palatability was due to the deterioration of the appearance, taste and stickiness of cooked rice. New rice grain from cultivars with a good eating quality showed a relatively high palatability aS compare with stored rice. The moduli of cooked rice grains of stored rice were increased and values of loss tangent of cooked rice was lower than those of new rice, such cases in poor palatability cultivars were much more obvious. The eating quality of stored rice was generally poor for the cultivars with a high free fatty acid content. In addition, the breakdown and maximum viscosity values in amylographic characteristics were slightly increased.
Sánchez-Marroquín, A; Maya, S; Domingo, M V
Forty-five harvests corresponding to the two predominating domestic species of amaranth in Mexico were studied. The proximate analysis revealed some statistically significant differences throughout three years of observation. The Ca, P and Fe content did not vary greatly in 15 samples. No chemical differences were either manifested in the Mercado and Aztec types of A. hypochondriacus, nor in the Mexican type of A. cruentus. The latter exhibits a higher grain yield and a shorter life cycle; however, its baking quality is apparently inferior to that of the Mercado type of A. hypochondriacus. The heat treatment of the seeds (toasting, popping and cooking) affected protein and lysine contents as does in cereals and leguminous seeds although toasting in particular improves its sensory characteristics without altering digestibility and PER. Popping only improves PER. Heating at 90 or 170 degrees C for three to five minutes, at the usual seed's moisture rate of 6 to 15%, does not affect protein content and does so only slightly in the case of the fatty acids content. Amylographic and farinographic values of the starchy fractions indicate similarities to C. quinoa and differences with respect to wheat. In the case of "amaranth milk", viscosity and gelatinization temperature produced satisfactory values. The extension of amaranth cultivation in the country is hereby suggested in view of the seed's nutritional quality, and considering the behavior of whole amaranth flour and its fractions.
KARAKTERISASI TEPUNG UBI JALAR (Ipomoea batata L. VARIETAS SHIROYUTAKA SERTA KAJIAN POTENSI PENGGUNAANNYA SEBAGAI SUMBER PANGAN KARBOHIDRAT ALTERNATIF [Characterization of Sweet Potato Flour (Ipomea batatas L. var. Shiroyutaka and Assesment of the potential as Alternative Carbohydrate Source For Food Product
Beni Hidayat 1
Full Text Available This research was aimed to characterize sweet potato flour var. shiroyutaka and assessment of its potential as alternative carbohydrate source on food product. Characterization was conducted on flour processed from sweet potato var. shiroyutaka harvested at four months was characteristic, these included whiteness degree and water absorption of the flour, ratio of amylase-amylopectin, form and size of starch granule, and starch digestibility.The research showed that whiteness degree and water absorption of the flour were 78,82% ( 0,52 and 1,25 g/g ( 0,12 respectively. The ratio of amylase-amylopectin, gelatinization temperature, maximum viscosity and invitro starch digest ability were 69.82%: 30.18%, 78-900C and 84,78% respectively. The granule of its starch was round form and with size 2-4 micron.The main potential of the flour is related with its specific characteristics which were the amylose-amylopectin ratio, the starch amylograph profile, form and size of starch granule, and the starch digest ability. These parameters implied that, the flour should be utilized in the production specific food products.
Rincón, Alicia Mariela; Padilla, Fanny C
Artocarpus altilis, seedless variety, is a fruit-producing plant which is cultived in Margarita Island, Venezuela, and is consumed by the inhabitants of the region. Its chemical composition and physical characteristics were determined. The chemical (AOAC and AACC methods), physicochemical, morphometric characteristics, viscoamylographic properties and digestibility in vitro of starch from Artocarpus were studied. The starch yield was 18.5 g/100 g (dw)w with a purity of 98.86%, 27.68 and 72.32% of amylose and amylopectin, respectively. Scanning electron microscopy showed irregular-rounded granules. Swelling power, water absorption and solubility values were determined and found to be higher than that of corn and amaranth starch. The amylographic study showed a gelatinization temperature at 73.3 degrees C, with high stability during heating and cooling cycles. Artocarpus starch could also be categorized in the group of mixed short chain branched/long chain branched glucan starches, this agrees with digestibility results that showed a high degree of digestibility in vitro. These results might be advantageous in medical and food use.
Full Text Available True-isogenic lines, differing only in the semi-dominant Rht3 dwarfing gene, were developed from the cross 'Tom Thumb x Bankuty 1201' during 17 years of continuous selection on heterozygous semi-dwarf plant. The effect of double (Rht3 Rht3 = full-dwarf, single (Rht3 rht3 =semi-dwarf, or no dwarfing gene (rht3 rht3 = tall dosage on some plant, seed, and flour quality traits were observed in the isogenic lines during two years field experiment, planted by 'honey-comb design' at Kri`evci, Croatia. Significant main effect of Rht3 gene was in shortening of plant height by 54% and 28% in double and single gene dosage respectively. Full-dwarf genotype (Rht3 Rht3 had by 12% more heads/plant, but the other yield components as number of grains/head, and grain weight/head were lower by 25 and 28% respectively, resulting in significantly lower grain yield/plant (-27%. However, this also could be a secondary side effect of prolonged vegetation influenced by doubled Rht3 gene. There was no significant effect on flour protein content. Double gene effect was strong and significant for maximum dough viscosity measured by amylograph in BU (101%. In our environment full dwarf (Rht3 Rht3 has no agronomic value, but single gene dosage could be of commercial interest in hybrid wheat breeding.
Arámbula Villa, G; Barrón Avila, L; González Hernández, J; Moreno Martínez, E; Luna Bárcenas, G
The corn tortilla is elaborated using corn grain masa processed by the traditional nixtamalization method, which consists of two steps: cooking and steeping. In these steps the physicochemical and structural properties are strongly affected, resulting in changes in the textural characteristics of the tortilla produced. In this work the effects of cooking and steeping time on the moisture content, amylographic profiles, crystallinity, weigh loss from masa to tortilla, starch damage, rollability, elasticity and cutting force for grain, masa and corn tortillas, were evaluated. The milling of the nixtamalized grain and the cooking of tortilla conditions were the same in all treatments. All tortillas samples showed a good rollability. The results show that the moisture content of corn grain was increased up to 42 g/100 g during the total cooking time (45 min), and it further increased to 52-53 g/100 g after when the cooked grain was steeped for 4 h. All evaluated parameters showed high correlation coefficients with the texture properties of tortillas. The starch damage was the variable with the best correlation among all evaluated parameters. The correlation coefficients between starch damage and moisture content, weigh loss and maximum viscosity for corn grain, masa and tortillas were larger than 0.92 (p tortillas were produced using nixtamal with the follow characteristics: moisture content of nixtamal, 42-44 g/100 g and tortilla, 43-44 g/100 g; adhesiveness of masa, 30-50 g; maximum viscosity of nixtamal, 860-880 cp and tortilla 490-510 cp; starch damage of nixtamal, 14 g/100 g and tortilla, 35-37 g/100 g, and weigh loss of tortilla during cooking, 16 g/100 g.
张民; 吴娜; 董家美; 王芳
采用压热处理、微波处理、超声波处理等方法对大米淀粉改性,用DSC、布拉班德粘度仪和扫描电镜等仪器测定了大米淀粉理化指标和颗粒结构.研究结果表明,与原淀粉相比,压热处理淀粉的To、Tp、Tm最高(143.61℃、159.82℃、170.30℃)；峰值粘度最低(142 BU)；抗酶解性最高(13.49％)；除超声波处理,其它方法改性的淀粉的溶解度、膨胀能力、凝沉性都有一定程度的升高,淀粉颗粒均已熔融为一体,无完整的颗粒存在.%Rice starch was modified by autoclaving, microwave and ultrasonic methods, respectively. Then its physicochemical properties and granule structure were explored by differential scanning calorimetry (DSC), Brabender amylograph analyzer, scanning electron microscopy (SEM) and other test methods. The results showed that, in comparison with native starch, the autoclaving treated starch showed higher values of To (143.61 ℃), TP (159.82 ℃) and Tm (170.30 ℃) Jiigher anti-enzymatic property (13.49%) and lower peak viscosity (142BU). The solubility, swelling power, retrogradation of autoclaving and microwave modified starches increased. These starch melted blend and showed no complete particles.
Pedro Luiz Manique BARRETO
Full Text Available Foram utilizadas carcaças residuais da filetagem industrial de tilápias (Oreochomis sp. na obtenção de carne de pescado separada mecanicamente (CPSM para elaboração de surimi. Amidos de diferentes fontes, como milho ceroso, milho ceroso modificado e mandioca, e o polissacarídeo carragena foram usados como ingredientes, e estudados seus efeitos no comportamento do gel de surimi. O surimi elaborado a partir de carcaças residuais da filetagem industrial, apresentou um rendimento final de 25% (peso/peso. A análise instrumental de textura apresentou um efeito fortalecedor, em relação à força de penetração dos amidos no gel de surimi, sendo esse efeito proporcional à viscosidade (r = 0,81, pFillet frames from industrial processing of tilapias (Oreochomis sp. was utilized to obtained minced meat for surimi. Starch from differents sources ( waxy maize starch, modified waxy maize starch and tapioca and the polysaccharide carrageenan was utilized like additives, and then studied their effects on surimi gel behaviour. Tilapia surimi showed a yield of 25% (weight/weight. The instrumental analysis of texture showed a strong effect of starch in relation to penetration force in surimi gel, these effect was proportional to starches viscosity (r = 0,81, p<0,05, studied by Brabender amylograph, by other hand, both starch and carrageenan showed a decresed in viscoelasticity of surimi gel (p<0,005.
Full Text Available The paper gives a brief overview of the current nutritional status of the Ukrainian population and describes useful buckwheat properties. The objective of the paper is to study the effect of buckwheat processing products (flour and flakes on the technological process and quality of bread made from whole-wheat flour. This paper describes and analyzes research data on the rheological properties of dough samples which were determined by farinograph and amylograph. Investigation of structural and mechanical properties of dough showed an increase in water-absorbing capacity in all samples when adding buckwheat products. Moreover, dough made with buckwheat flakes has a lower value of mixing tolerance index (by 47 % than dough made from buckwheat flour, and a higher valorimetric value (by 20 %. Determination of dough properties by amylogram has shown that a sample containing buckwheat flakes has a higher maximum viscosity than a sample containing buckwheat flour. Determination of the gas-production and gas-retention capacity of dough is also presented, along with an analysis of the quality of finished products based on the results of laboratory baking tests. The samples of bread supplemented with buckwheat flakes have better shape stability (by 21 %, specific volume (by 12 % and porosity (by 11 % than bread made from buckwheat flour. The organoleptic evaluation of finished product quality has shown that bread supplemented with buckwheat flakes has a more fluffy-texture, elastic crumb and uniform porosity than bread made from buckwheat flour. Buckwheat flakes proved to have a better effect on parameters of the technological process and quality of bread when compared with buckwheat flour.
谢新华; 王娜; 潘治利; 艾志录
为了解脂肪酸对稻米淀粉糊流变特性的影响,利用旋转黏度仪测定了月桂酸、豆蔻酸、棕榈酸和硬脂酸与稻米淀粉结合形成复合物后淀粉糊的流变特性.结果表明,分别将1.0%、2.0%和3.0%的脂肪酸添加到稻米淀粉中,在95℃下蒸煮5、10和15 min,复合指数随脂肪酸量的增加而增加,随碳链增加而降低;黏度系数随复合物的增加而增加,而流变指数则随复合物的增加而降低;在4种脂肪酸中月桂酸与淀粉形成复合物的能力最强,对稻米淀粉的流变性影响最显著.%The effects on rheological properties of the starch - lipid complex of rice starch mixed with lauric,myristic, palmitic and stearic acid were measured by a viscometer. The theological properties of starch and correlative influencing factors were discussed. The results showed that different fatty acids were added to rice starch, at 1.0％,2.0％ and 3.0％ levels ,and cooked in a visco-amylograph at 95 ℃ for 5,10 and 15 min. The complex index progressively increased with the increase in levels of fatty acids and decreased with the increase of carbon chain. The viscosity coefficient increased with the increase of the complex. The theological index decreased with the increase of complex.Lauric acid had the highest ability to form the complex. The effect of lauric acid on the rheological properties of rice starch were the most outstanding in four fatty acids.
Full Text Available Sago (Metroxylon sagu Rottb. is a potentially starch source crop. However, in West Kalimantan the use of sago is still limited. There is lack information about sago starch characteristics in relation to growth stages of the palm. Therefore, this study was aimed to observe the characteristics of sago starch extracted from the trunk at variatious growth stages. Sago trunks were taken from Sui Bemban and Sui Ambawang villages, Kubu Raya regency, West Kalimantan. They were classified into four different physiological growth stages, namely dewasa (9 yr, jantung (10 yr, rusa (11 yr, and bunga (12 yr old. The starch was extracted in laboratory and then dried at 50 °C. Dried sago starches were analyzed for their chemical compositions (moisture, fat, protein, ash, carbohydrate, fibre, and amylose contents, physical cha- racteristics (colour and the granule form, functional characteristics (water absorpsion, oil absorpsion, swelling power, and solubility. Pasting properties were characterized by Brabender amylograhpy. Results indicated that chemical composition and physical characteristics of the sago starches extracted from 9-12 year-old trunks were not signifi- cantly differrent. The highest rendement obtained from 10 – 11 year-old trunks. Amylose content was 41.8 % which was categorized as high. Functional characteristics as shown by the amylograph revealed that sago starch has type-C curve. Starch extracted from 9 yr old trunk gave the highest paste viscosity which was the most suitable for for use in product that needs a strong gelling property. ABSTRAK Sagu (Metroxylon sagu Rottb. sangat potensial sebagai sumber pati, namun di Kalimantan Barat pemanfaatan sagu sebagai sumber pati masih terbatas. Belum ada informasi mengenai hubungan tahap pertumbuhan dengan sifat-sifat pati sagu yang dihasilkan. Penelitian ini bertujuan untuk mengetahui karakteristik pati sagu pada beberapa tahap pertumbuh- an. Tanaman sagu diperoleh dari Desa Sui Bemban dan
Luciana Pereira Lobato
Full Text Available O objetivo deste estudo foi investigar o efeito combinado de inulina, amido e leite nas características texturais de géis e de propriedades de pastas empregando o planejamento experimental de misturas. Foram avaliados o perfil viscoamilográfico e a firmeza dos géis. Em todos os parâmetros avaliados, os modelos ajustados mostraram-se influenciados pela presença de inulina, amido e leite, assim como de algumas interações desses ingredientes. A viscosidade máxima e a viscosidade final foram influenciadas positivamente pela concentração de amido e negativamente pelas interações deste com leite e com inulina. A firmeza dos géis aumentou com o aumento do teor de amido, mas a interação amido-inulina foi antagônica, contribuindo para diminuir essa característica. O efeito da interação entre amido e inulina pode ser explicado pelo fato de que a inulina possui maior afinidade pela água, em relação ao amido, ou, ainda, por agir como diluente, fazendo com que haja menor contato entre os grânulos e/ou cadeias de amido. A partir dos resultados encontrados neste estudo, verifica-se que a inclusão da inulina em sistemas amido-leite pode influenciar nas características texturais e de viscosidade, possivelmente refletindo-se nas características sensoriais. Com isso, a avaliação das interações com outros ingredientes da formulação torna-se essencial.The objective of this work was to investigate the combined effect of milk, starch and inulin on the textural characteristics of gels and on the pasting properties, using an experimental mixture design. Gel firmness and the amylographic profile were evaluated. For all the parameters evaluated, the fitted models were shown to be influenced by the presence of inulin, starch and milk, as also some of the interactions between the ingredients. The maximum viscosity and final viscosity were positively influenced by the starch concentration and negatively by interactions between the starch and