Wörterbuch „Stärke”︁. Teil 2

Vocabulary “Starch”. Part II. After comprehensive preliminary work by the Working Group “Terminology” of the Technical Committee “Starch, Including Derivatives and By-Products” of the International Standardization Organization ISO (WG 10, ISO/TC 193) a vocabulary of important terms of the starch chemistry and starch technology in English and French language was made available. G. Graefe reported in this journal from time to time about the state of this work [Starch/Stärke 16 (1964), 229–232 and 381–385; 17 (1965), 263–268; 23 (1971), 103–111; 27 (1975), 56–61 and 131–134]. The second, and for the time being last amendment of the vocabulary was edited at 1. 6. 1979 as International Standard ISO 1227–1979 (E/F). In the following the collection of technical terms which exists corresponding to the ISO regulations only in English and French language is made available together with a non obligatory translation into the German language to a bigger community of interest.     

Internationale Normung von Begriffen und Definitionen auf dem Stärkegebiet 6. Mitteilung

International Standardization of Terms and Definitions Associated with Starch. Part 6 . As a result of the sixth meeting of the „Terminology”︁ group (SC 1/WG 1) of Technical Committee 93 (TC 93) of the International Standardization Organization (ISO) held in Paris on October 22 and 23, 1974, a list was compiled giving definitions in English and French fo another 27 terms. The French version (a), the English version (b) and an unofficial German version (c), supplemented by alphabetic indices, are presented for discussion. It is planned to submit these terms and definitions to the „P”︁ members of TC 93 for acceptance and to incorporate them as third supplement in International Standard 1227. The „Terminology”︁ group has thus terminated its work for the time being.     

5th Plenary Meeting of ISO/TC 93 in Paris

This article will report on the course and the result of the 5th Plenary Meeting of Technical Committee 93 of the International Organization for Standardization (ISO) which deals with standardization of analytical methods and test processes in the field of starch and its derivatives and by-products. By invitation of the French Standardization Committee ”︁Association Française de Normalisation„ (AFNOR) it was held on Thursday 16, March and Friday 17, March, 1972, in Paris. There will be a report on the resolutions which were passed as recommendations in the course of the 2-days Plenary Meeting as well as on resolutions passed – also as recommendations – by the two Sub-Committees SC 1 ”︁General Problems„ and SC 3 ”︁Starch Hydrolysates„. The latter committees had been newly constituted by the Central Secretary's office during reorganization of the entire ISO/TC 93 in 1970 without questioning or consent of the technological experts. These committees gathered also in Paris fo the first meeting after their constitution on the 14th and 15th of March.     

Internationale Normung von Begriffen und Definitionen auf dem Stärkegebiet 5. Mitteilung

International Standardization of Terms and Definitions Associated with Starch. Part 5 . As a result of the fifth meeting of the “Terminology” group (SC 1/GT 1) of Technical Committee 93 (TC 93) of the International Standardization Organization (ISO) held in Berlin on February 19 and 20, 1974, a list was compiled giving definitions in English and French for another 40 terms. The French version (a), the English version (b) and an unofficial German version (c), supplemented by alphabetic indices, are presented for discussion. A total of 127 terms and definitions of the international vocabulary, approved by 20 countries, have up to now been published in International Standard 1227 of February 15, 1973 and its first supplement of March 15, 1974.     

Technology Assessment on Renewable Raw Materials: Potentials and Risks of the Use of Starches

Starch as a renewable raw material for chemical/industrial uses has a long tradition. In terms of quantity, starch ranks third behind wood and vegetable oils. In the medium term, this position will be maintained, if not improved. The volume of renewable raw materials used for fuel is even greater and expected to increase in the medium term. By means of a technology assessment on chemical/industrial and energy uses of renewable raw materials, it shall be demonstrated where the specific potentials and risks of starch use can be found. Among others, the following aspects are considered: energy and CO₂ balance sheets, biodegradability and competiveness. Under the headings of „saving of raw materials (degree of self-sufficiency)”︁, „area required (reduction of surpluses)”︁, „employment effects”︁, „contribution to CO₂ reduction”︁ and „need for subsidies”︁, medium-term (up to 2005) potential use of starch in Germany is studied relative to use of renewable raw materials in total.     

Kritische Untersuchungen über Bildung und Entwicklung der Triticeen-Stärkekörner

Critical Examination of the Development of Triticeae Starch Grains. At the right time when the first antheres appear at the top of the ears large quantities of point-shaped starch grains are to be seen in the young ovary. From there the diameters of the small starch grains have been measured until milky maturity. In this way the identity and the growing of the small starch grains had been confirmed. After some days when diameters of the small starch grains reach 4–6 üm a second step of development begins. The starch grains are progressively surrounded in the equatorial planes by a consurrounded continually enlarging structure which resembles two lips with a furrow between them. When the two lips surround the „nucleus”︁ thickness and diameters of the granule continue to increase in such a way that the furrow becomes shallower and is present in the mature beconvex structure only as a shallow score.     

Beobachtungen über die Viskositätseigenschaften niedrig substituierter Stärkeacetate

Observations on Viscosity Properties of Low-Substituted Starch Acetates. It was shown that with low-substituted starches dispersibility in water increases with increasing content of acetyl groups and increasing temperature. This fact becomes evident in lower temperatures at the beginning of pasting and at maximum of „viscosity”︁-graph. This has confirmed and extended earlier observations. Viscosity of starch acetate pastes is lower in cold as well as in hot state as that of native starch paste. Viscosity decreases down to an acetyl content of 2.36% and it changes only unnoticeably above that point. The decreasing gel forming ability can be expressed by the ratio of paste viscosities in cold and hot state. The rotation viscosimeter Rheotest proved well applicable for studies of viscosity and rheological properties of starch and of low-substituted acetates.     

In vitro Digestibility of Starch from Native and Germinated Pigeon Pea (Cajanus cajan L.)

The in vitro digestibility of native and germinated pigeon pea starches both in raw and cooked forms were investigated. The rate of digestibility (glucoamylase) was different for the two raw starches. There was a preferential utilization of low molecular weight ‘amyloses’ in the germinated samples, during in vitro enzymatic digestion of the raw granule. On acid hydrolyses, germinated samples produced lower molecular weight fragments than did raw starch, though the rate of reducing sugar released was not different. It may therefore be concluded that the size of the „amylopectin”︁ molecule is smaller in germinated starch. The easy availability of low molecular weight „amyloses”︁ may also influence the greater susceptibility of germinated starches to amylolysis even after cooking.     

Hafer,Gerste und Triticale — Eigenschaften und Chancen für die technische Stärkegewinnung

Oats, Barley and Triticale — Properties and Chances for the Industrial Starch Production. Process development for the recovery of novel materials from agriculture for chemical and technical utilization has become a main point in the research program „Renewable Resources”︁ of the Federal Ministry of Nutrition, Agriculture and Forestry. In preliminary investigations oats, barley and triticale were tested for the development of starch manufacturing processes. Cereal milling techniques and methods for separation of starch, protein and fibre were predominant with water extraction, screening and centrifugation techniques which can be realized in technical scale. Process water recycling, acid treatment and separation of proteins reduced COD values to 50%. Starches with high percentage of small granules will get more importance for the production of novel technical and chemical derivatives. Methods for concentration and isolation of fine fractions were studied and controlled by electron microscopy. The starches showed differences in stability to alkali treatment and in viscosity characteristics.     

Characteristics of Gel-chromatographic Fractions of Starch in Relation to Rice and Expanded Rice-Product Qualities

Starch from waxy and nonwaxy rices was separated on Sepharose. In nonwaxy rice, the major (void volume) fraction stained a varying shade of blue with iodine depending on the sample. The water-insoluble amyolose content as estimated in milled rice flour was highly positively correlated with the λ_max of the iodine colour as well as with the „amylose”︁ content of the fraction. Debranching with pullulanase showed that the fraction had the dual character of being both amylopectin and amylose. A second fraction was for the most part true amylose. The volume of expanded rice product seemed to increase with average molecular weight of starch. The highest average molecular weight of starch corresponded to analytical values of water-insoluble amylose as estimated in rice flour and the same corresponded to the greatest expansion volume.     

Artefacts au cours de la préparation de coupes de grains d'amidon. Etude par microscopie photonique et électronique

Artefacts During the Preparation of Sections of Starch Granules. Studies under Light and Electron Microscope. Dark bands which are usually observed in ultrathin sections of starch granules, „coloured”︁ or not, have been considered by some authors as marking the presence of protidic substances, by others as artefacts of sectioning, on account of the diversity of their shapes and the frequency of their appearance. Examinations under light microscope show that this phenomenon appears effectively, during the sectioning of the inclusion block, when the ultrathin section of starch comes into contact with the surface of water in the collecting tank and then swells. The examination under electron microscope of ultrathin sections shadowed with gold, allows us to show that these dark bands are the consequence of surface folding of the cut starch grains. The measurements of electron density show that there are folds like S or double folds like S, and that electron transmission across the sample follows a logarithmic rule. A discussion leads to think that these artefacts are the consequence of a defective permeation of starch with the inclusion material and the result of starch water affinity. We must definitely leave out that dark bands should be a manifestation of protidic material.     

Effect of lactic fermentation and extrusion of bean and pea seeds on nutritional and functional properties

Controlled lactic acid fermentation of „Bomba”︁ bean and „Opal”︁ pea was used to improved their nutritional and functional properties. The modified legumes were used as a source for extrusion process to obtain snack-type foods. Milled legume seeds were fermented by different population of Lactobacillus plantarum with different moisture content in plant material to estimate the influence of this two parameters on the dynamics of lactic fermentation. Quantitative and qualitative changes in carbohydrates and nitrogen compounds of modified seeds were analyzed (e.g . mono- and oligosaccharides, "in vitro" starch and protein digestibility). In the new snack-type products, functional properties: water solubility index (WSI), water absorption index (WAI), expansion index, bulk density and texture explained as a shearing stress were recorded. Results showed a distinct decrease in raffinose, verbascose and stachyose contents even up to 80 - 90% after fermentation and extrusion process. Lactic fermentation and extrusion of bean and pea seeds contributes to a significant (a ≤ 0,05) increase of "in vitro" protein and starch digestibility. Observations of changes in functional properties of extruderates (e. g., expansion, shearing stress, WSI, WAI) allowed to choose the most efficient model of fermentation pretreatment to obtain the best improvement of nutritional and functional features of the product.     

Weizenstärkekörner. polarisationsoptisch und elektronenmikroskopisch

In earlier studies since 1961 [1] the author has observed that the A type starch granules of Wheat and other Hordeae show between crossed Nicols in most cases differentiated polarization crosses. In the center of these there is a little high double refracting disk with a small dark polarization cross. In the broader outer zone, which is not so bright, the armes of the small cross are persued much broader and indistinct. A. D. Evers (1971) has shown with the scanning electron microscope that the development of A type starch granules begins with an initial minute spherical granule, which becomes a „nucleus”︁, and which is progressively surrounded in the equatorial plane by a continually enlarging structure which resembles two lips with a furrow between them. When the lips have surrounded the „nucleus”︁ the thickness and diameter of the granule continue to increase in such a way that the furrow becomes shallower and is present in the mature biconvex structure only as a shallow score.     

New Starches VI. The Structure of the Starch Chunks from Amaranthus retroflexus

The structure of the starch chunks from „Amaranthus retroflexus”︁ have been examined by light and electron microscopy. It has been established that these chunks exist as such in the seed and that they are not artifacts of the method of preparation. Treatment with crystalline a-amylase suggests that the chunks are made up of small granules cemented together with amorphous starch. Electron micrographs suggest that the chunks result from the filling of an endosperm cell with starch.     

Über den Einsatz natürlicher Binder bei der Papierherstellung und -veredlung

The Use of Natural Binders in Paper Making and Surface Applications. Binders are used in paper making for improvement of web strength and in surface operations – here particularly in coating – for gluing the pigments applied to the paper surface onto the same. As „natural binders”︁ those are meant here, which are of plant or animal origin and which are used as solutions or colloidal solutions. That is a distinct boundary towards the synthetic dispersions, which dominate the field today. Starch excels in economic importance among the natural binders. In order to strengthen the web structure cationic starches are used in the furnish. By the help of a size press the surface improvement of the paper can be done within the paper machine. Here native and degraded starches are predominant. In the case of paper coating fine pigment particles are applied to the paper surface in order to obtain a smoother paper surface with improved printability. The pigments must be held to the paper by a binder. Even as the use of starch for this purpose of pure binding power is more economic in comparison to synthetic latices, they are nevertheless here dominant. The reason for this are problems, which show up in printability of coated starch containing paper surfaces. They are reduced ink reception and migration of starch during drying of the coatings. It should be possible that in cooperation between the paper and the starch industry existing problems in the use of starch can be solved or diminished in order to obtain an increased application of starch in the paper industry in the future. This, in the case of market acceptable prices, would be in the interest of both industries.     

Per-O-methylated α- and β-CD: Cyclodextrins with Inverse Hydrophobicity

The investigation focuses on the computer-aided generation of the molecular geometries, contact surfaces, and lipophilicity patterns of per-O-methylated α-CD ( 1 ) and its β-CD homolog 2 , and compares them with their parent non-substituted cyclodextrins. The molecular geometries, compared via statistical analysis of crystal structure data available, reveal 1 and 2 to be considerably more flexible than α-and β-CD, allowing wide variations in the tilting of the glucose units relative to the macrocyclic ring axes. The comparative evaluation of their contact surfaces not only discloses a substantial increase of the torus heights upon per-O-methylation (from ∼8.0Å in α- and β-CD, to → 11.1Å in 1 and 2 ), but also an enlargement of their cavity areas by 40% (+35Ų for α-CD → 1 ) and 70% (+75Ų for β-CD → 2 ), respectively. The hydrophobic characteristics of 1 and 2 , emerging from the molecular lipophilicity patterns (MLPs) generated and projected onto the contact surfaces in color-coded from, are inverse to those for α- and β-CD: the most hydrophobic surface regions of 1 and 2 are located at the torus rims made up by the 2-OMe and 3-OMe groups at one side, and the 6-CH₂OMe moieties at the other, with a hydrophobic „band”︁ wrapping around the outside of the macrocycles; these „exo-lipophilic”︁ topographies are opposed by pronouncedly hydrophilic central cavities. A variety of experimental findings can be rationalized on the basis of the opposite lipophilicity profiles of the CDs and their permethylated analogs, such as for example the opposite orientation of benzaldehyde, p-nitrophenol, and 3-iodopropionic acid in the cavities of α-CD and of 1 . Thus, the notion is substantiated that the operation of dispersive interactions between guest and CD-host cavities play a more dominant role in inclusion complex formation than hitherto appreciated.     

Properties of Rice Starch from Paddy Stored in Cold and at Room Temperature

Brabender viscograms of rice flour from aged paddy (stored at room temperature, RT 20°-33°C for 15 months) of two high amylose finegrain cultivars showed higher paste viscosities than that from the paddy stored at 4°-6°C (cold) for the same period. The differences were almost eliminated in case of isolated starches. The total amylose content was same for the starches from both aged (RT stored and cold stored) paddy. However, the hot water soluble amylose content was less in starches from „aged”︁ paddy. The number average molecular weight (M _n) as well as the swelling power and solubility of the starches from RT stored (aged) paddy were also less indicating that the aging of rice could partly be associated with the changes in the physicochemical properties of its starch.     

Characteristics and “Fodal”-Factor of Mango Seed Kernel Starch

Starch prepared from mango seed kernels is characterized by a low protein and fat content. Infrared studies proved the presence of amine and carboxyl groups of amino acids at wave numbers of 1485 and 1650 cm⁻¹ respectively, whereas the phosphate group had been detected at 1150 cm⁻¹. The contents of amylose and amylopectin were 39.9 and 60.1 respectively, reducing value was 1.54 and the alkali number was 10.10. The percentage of soluble material associated with starch was 2.11, whereas the percentage of branching of the mango seed kernel starch was 4.23. The glucose residues per end group were 23.62 and those per a segment were 11.81. Corn starch showed approximately the same values, whereas rice starch showed different results. The intrinsic viscosity was 1.72, 1.83 and 1.33 for mango seed kernel, corn and rice starches respectively, and the corresponding “Fodal” factors were 0.947, 0.983, and 0.992. X-ray analysis indicates that mango seed kernel starch possesses an “A” type of X-ray diffraction diagram.     

Towards Understanding Formation and Stability of Cyclodextrin Inclusion Complexes: Computation and Visualization of their Molecular Lipophilicity Patterns[1]

Five cyclodextrin inclusion complexes - typical examples for their solid state as well as exemplary „frozen molecular images”︁ of their status in solution - were subjected to a molecular modelling study comprising the computer-assisted generation of the molecular lipophilicity patterns (MLP's), i. e. the p-iodoaniline inclusion into α-CD, the complexes of β-CD with 1,4-butanediol, adamantane-1-carboxylic acid, and adamantane-1-methanol, and the unique 12-crown-4 ether inclusion compound of γ-CD. Based on their solid state structures, the „solvent-accessible”︁ contact surfaces were generated by the MOLCAD program. Calculation and color-coded projection of the MLP's onto these surfaces easily allows to locate the hydrophobic and hydrophilic surface regions of CD-host and guest alike. Their detailed analysis revealed a far-reaching, mostly complete conformity between the hydrophobic surface areas of the guest and the hydrophobic domains in the CD cavity. This striking tendency to optimize the reciprocal concurrence of lipophilic as well as hydrophilic domains at the guest-host-interface may accordingly be concluded to be an important, if not the decisive element in orienting the guest into the cavity and in determining the stability of the complex, particularly in cases where the guest is devoid of polar groups; if these are present, dipole-dipole alignments and the need for their solvation may diminish the importance of hydrophobic attractions for orienting and stabilizing the guest in the CD cavity.