Studies on Rye Starch Properties and Modification. Part II: Swelling and Solubility Behaviour of Rye Starch Granules

Rye starch shows the typical inhibited swelling behaviour of triticeae starches with an onset of swelling at rather low temperature (50–55°C). Swollen rye starch granules exist as individuals even after swelling at 100°C. The total dispersion of rye starch needs temperatures above 120°C with pressure cooking. On heating of the rye starch suspension preferentially amylose is leached. Defatting of rye starch exhibits no influence on swelling power but results in higher solubility and in increased amylose leaching. The drying procedures applied here resulted in stronger assoziation of the polymer molecules in the starch granule leading to higher swelling temperatures and a reduced solubility. Shiftings of the crystalline/ amorphous-ratio of the starch granules as caused by different drying procedures, had no influence on the results of swelling power investigation but the highest swelling enthalpy as well as Brabender viscosity were exhibited by a sample dried at room temperature. It is proved to be possible to change the swelling behaviour of rye starch to “potato starch type” by slight chemical modification like succination.     

Studies on Rye Starch Properties and Modification. Part III: Viscograph Pasting Characteristics of Rye Starches

Pasting characteristics of native as well as of physically and chemically modified rye starches have been characterized and compared with the other triticeae starches and starches from maize and potatoes. Normal and pressure viscograph techniques were applied. Additional, ridgelimetry investigation were performed with the gels formed from the viscographically prepared pastes. Rye as well as wheat and triticale starches exhibit unique, typical gelatinization behaviour, late onset of consistency gain, low but highly stable cooking consistency, consistency gain of the two-threefold on cooling. Gels are of statistically lower firmness as those of maize starch. Higher degrees of consitency, good cooking stability and high consistency gain on cooling were achieved after treatment in the pressure viscograph (max. temp. 120°C). Physical treatment like annealing, heat-moisture treatment, extraction by aqueous solvents, drying procedures result in different but in each case typical change of properties: shift of onset consistency gain, lower maximum consistency values, lower consistency gain on cooling. Gelfirmness will be enhanced in every case. The pasting characteristics of heat-moisture treated wheat starch differ from this by remarkably higher consistency values. Possible reasons for this are discussed. Succination (0.7-2.1%) changes the pasting characteristics towards the potato starch type, lower onset temperatures of consistency gain, very high values in maximum consistency, diminished cooking stability. The gels formed are smooth and turbid. Acetylation (0.7-2.3%) changes the pasting characteristics towards the maize starch type, maximum consistencies are lower compared with succinated triticeae starches. Ac contents of 0.7% inhibit the formation of rigid gels.     

Studies on the Biosynthesis of Starch Granules. Part 7. Compound Granules in Potato Starch

The nature of compound starch granules in potato starch is examined. The relevance of this investigation to the possible formation of potato starch is discussed, and a mechanism for synthesis of compound granules proposed.     

Studies on the Biosynthesis of Starch Granules. Part 9. The Starch Granules from Wrinkled-Seeded Peas

The nature of the complex granules of wrinkled-seeded pea starch has been examined, and related to changes in the starch during growth. An earlier hypothesis for the development of pea starch is shown to be untenable in the light of this information, and possible alternative mechanisms for the biogenesis of pea starch are discussed.     

Characterization of Pinhão Starch. Part I. Extraction and Properties of the Starch Granules

The starch fraction of Pinhão, the seeds of Pinheiro do Paraná (Araucaria angustifolia, Bert, O. Ktze) was easily extracted and represents 21.87% of total weight. The low content of protein, fat and ash accounts for the efficiency of the extraction and purification. Pinhão starch shows an amylose level and strong anionic characteristic similar to corn starch. The round-shaped granules are smaller than those of cassava and similarly resistent to DMSO solubilization, what suggests a very homogenous granular structure.     

Studies on the Biosynthesis of Starch Granules. Part 6. Properties of the Starch Granules of Normal Barley,and Barley with Starch of High Amylose-Content,During Growth

The granular morphology of two types of barley starch, widely different in amylose-content, has been investigated during the period of starch accumulation. The pattern by which the granules were laid down was markedly different, despite the previously observed similarities in the changes in the ratio and nature of the starch components.     

Lablab Bean Starch. I. Properties of its Granules and Pastes

The variety of lablab bean (Dolichos lablab) starch studied by the authors, presents smaller-sized, rounded granules, and others, larger ones, which are generally oval-shaped and measure up to 30 micra. These latter show 1, 2 or 3 polarization crosses under polarized light. The gelatinization temperature of the granules varies between 65–70–76 °C and iodine affinity shows a value of 6.05. Graphs were drawn for the swelling power, percentage of solubles, Brabender viscosity of the hot and cold pastes, and also for the observation of the effect of a-amylase on these pastes. It was observed that the starch pastes present the cross-linked type Brabender viscosity curves, which greatly resemble those of the chick pea, yellow pea and navy bean starches. Several theories relating to the composition and structure of the starch, and which might explain its behavior, were approached by the authors.     

Studies on Starch Granules

In X-ray diffractometric studies on starch granules of many kinds of plant species, we found a variety of intermediate C-type patterns. In particular, specimens of sweet potato starch granules varied from nearly the A-type pattern to nearly the B-type pattern. In these studies, we also found that spheroids of short chain amylodextrin showed very sharp diffraction patterns and that we could form amylodextrin spheroids with various types of X-ray diffraction patterns by varying the conditions of recrystallization. Then we showed that the X-ray patterns and physical properties of many kinds of cereal and root starches varied to some extent depending on the environmental conditions prevailing during the growth period. We examined the formation and the growth of starch granules in corn endosperm and the inner structures of these granules from the beginning to the end of their maturation by electron microscopic observations. We proved also, the appositive growth of starch granules using radio-active carbon dioxide. Then we tried to form starch granules in vitro. But the spheroids obtained from solutions of starch components were entirely different from natural starch granules. From the findings in these experiments, an ultramacromolecular concept of the starch granule is proposed.     

The Modification of Starch by High Pressure. Part I: Air- and Oven-dried Potato Starch

Air and oven-dried potato starch was compressed at 0.8–1.2 × 10⁹ Pa for 60 to 600s. Structural studies have shown that observed changes are both pressure and time dependent. The amylopectin shell of starch grains is the component which suffers most essential but rather random damage. The high pressure of 1 × 10⁹ Pa seems to cause some repolymerization of dextrin formed first under compression. The 1.2 × 10⁹ Pa pressure causes further damage of the structure with ordering of the molecules into more crystal-like matter. The compression of the air-dried starch provide the formation of hard solid gels.     

Tepary Bean Starch. Part I. Physico-chemical Properties

Starch of high purity was isolated by a simple procedure from tepary beans (Phaseolus acutifolius var. latifolius). Granules were spherical to oval with a birefringence pattern similar to that of other legume starches. Under SEM they appeared smooth with no evidence of fissures. They showed a normal distribution of diameters with a range of 15.5–59.8 μ and a mean of 33.5 μ. Tepary starch had an amylose content of 30.7% and a gelatinization temperature range of 70.5–84.0°C. Other properties were also determined. Fractionation provided an amylose fraction with a β-amyloysis limit of 76.3% and an average DPη of 618. The amylopectin fraction had an average values of 33, 22 and 10 glucose units respectively.     

Buffalo Gourd Root Starch. Part I. Properties and Structure

The structural and physico-chemical properties of starch isolated from three genetically different populations of buffalo gourd (Cucurbita foetidissima HBK) were explored. The proximate composition of this starch was found to be similar to that of other starches. Granules were depicted to vary in shape (round, oval, truncated) and to resemble maize starch in size. A change in X-ray diffraction behavior from a B- to a C-type pattern was observed upon autoclaving raw gourd starch. Average physico-chemical values were reported as follows: amylose content, 23.1%; water binding capacity, 112; and gelatinization temperature range, 61–69°C. Variation in alkali numbers among samples of this starch was extensive. A highly ordered internal structure of the granule was suggested by low values of swelling power and solubility and high initial pasting temperatures. Pasting curves of buffalo gourd starches were developed which revealed stable gel viscosities throughout the temperature cycle. Amylose fractions were found to be resistant to β-amylase attack and exhibited an average DP η of 1915. Amylopectins were shown to have an average DP η of 2000, and an OCL to ICL of 1.3 to 1.     

Studies on the Biosynthesis of Starch Granules. Part 8. A Comparison of the Properties of the Small and the Large Granules in Mature Cereal Starches

Starch from four samples of barley and three of wheat has been isolated by two techniques. The total starches were divided into subgroups differing in average granular size, and the relative weights and the amylose-contents of these sub-groups were determined. In the normal cultivars, the amylose-content of the starch was shown to be independent of granule size.     

Cereal- and Root Starch Modification by Heat-Moisture Treatment. I. Physico-Chemical Properties

Effects of heat-moisture treatment of varied severity on physicochemical parameters of three cereals (barley, triticale and red millet) and two tuber starches (arrowroot, cassava) were studied. The treatment produced restriction in swelling powers of all tested starches; solubilities of cereal starches increased while those of the tuber starches were reduced at 90°C, indicating different types of reorganization of the starch polymers in the two types of granules; enzyme susceptibilities and water-binding capacities were augmented by the treatment. X-ray diffraction studies showed decreases in degree of crystallinity of cereal starches and changes of C-pattern to A-pattern of tuber starches by the treatment. Effects on pasting properties are also given.     

Chemical Modification of Proteins Part 6. Further Studies on Gelation of Casein after Modification by Dialdehyde Starch

The physical and chemical changes in casein during the gelation owing to the chemical modification by dialdehyde starch (DAS) in 8–10% solution were studied using electron-microscopy, measuring the mechanical properties (shear deformation), turbidimetric titration, and determination of amino groups. The gelation which proceeds during a storage time of 2 weeks is accomplished by the formation of a super-molecular network structure. Depending on the conditions of modification (pH, percentage of DAS, protein concentration) a more or less dense network is formed. An increase of pH (in the range of pH 6,3–9,7) leads to an increase of gelation speed, which favours the formation of irregular network structures. The denser the network formed the smaller is the shear deformation measured by the device of Tolstoi. During the storage of the gels the plastic component of compliance decreases to a greater amount than the elastic one. Therefore the relative amount of elastic component increases. During the reaction with DAS the maximum of turbidity of the protein (solubility minimum) shifted to lower pH owing to a blockage of positively charged groups. On the contrary to the changes measured by physical methods, this shift is complete soon after a 1 day storage. Similarly the blockage of amino groups is finished in the most cases this time too.     

葛根淀粉颗粒性质的研究

本文对葛根淀粉颗粒的性质进行了研究，包括淀粉颗粒的大小、形貌、X—射线衍射图谱、α—淀粉酶的酶水解作用方式等，并与玉米淀粉进行了比较。结果表明：葛根淀粉平均粒度为24．08μm，小于玉米淀粉的38．97μm；葛根淀粉和玉米淀粉颗粒的偏光十字接近颗粒中心，但葛根淀粉颗粒的偏光十字不明显；葛根淀粉的X—射线衍射图谱为C型，玉米淀粉为A型，而两者的结晶度分别为18％和37％；葛根淀粉和玉米淀粉对α—淀粉酶的作用极为敏感，但在酶解方式上，葛根淀粉是在淀粉粒表面形成许多微孔并经脐心进入淀粉粒内部，而玉米淀粉则是被层层水解，在淀粉粒表面形成很少的微孔。     

魔芋淀粉改性研究

用魔芋淀粉,氯乙酸和氢氧化钠为原料,在乙醇溶液中制备高粘羧甲基淀粉,用正交试验设计试验考察了物料配比、反应温度和反应时间对产品性质的影响,确定了最佳反应条件。     

Studies on the Biosynthesis of Starch Granules. Part 5. Properties of the Starch Components of Normal Barley,and Barley with Sturch of High Amylose-Content,During Growth

Changes in the molecular components of barley starch, from related genotypes of barley differing in amylose-content, have been investigated over the period of reserve-starch deposition in the plants. Striking similarities in the changes in amylose-contents, and in the fine structure of component amylose and amylopectin fractions, were observed over this period, despite the large differences in the types of starch.     

Optical Interference Studies on Single Starch Granules

Studies on the optical interference by potato, sorghum, wheat, pigeon pea and cowpea starch granules indicated that the potato granule was ordered mostly on the centre of the granule and that the molecular arrangement of the birefringent portion was perpendicular to the radial. This was more so with the legume starches where the entire granule was ordered. Cereal starches had birefringent material on the periphery and non-birefringent material in the centre and in this case, the birefringent material was radially arranged.     

Structure of Starch Granules. Part 3. Some Considerations on Leguminosae and Tuberosae

It is considered that the granules of Leguminosae and Tuberosae starches generally present crystalline structures with X-ray diffraction patterns of the C type. The results obtained by the authors with starches from different species and from different varieties of a single botanical species were compared with those obtained using solubilization techniques, as with dimethylsulfoxide or by enzymatic action and the conclusions arrived at are different, in some cases, from the generally established concepts.     

黄姜淀粉的基本性质研究

本实验运用电子显微镜、X-衍射、布拉本德黏度仪等分析仪器对黄姜淀粉颗粒形态、晶体结构、理化特性、糊化特性进行研究。结果表明:黄姜淀粉的颗粒表面光滑,平均粒径13.52μm,总淀粉含量73.4%,其中直链淀粉为23.6%。