Wörterbuch „Stärke”︁. Teil 1

Vocabulary „Starch”︁. Part I. 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 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.     

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.     

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.     

Mechanical and Microstructural Properties of “Wet” Alginate and Composite Films Containing Various Carbohydrates

Composite “wet” alginate films were manufactured from alginate–carbohydrate solutions containing 5% alginate and 0.25% pectin, carrageenan (kappa or iota), potato starch (modified or unmodified), gellan gum, or cellulose (extracted or commercial). The “wet” alginate films were used as a model to understand co‐extruded alginate sausage casings that are currently being used by several sausage manufacturers. The mechanical, optical, and microstructural properties of the calcium cross‐linked composite films were explored. In addition, the water holding capacity and textural profile analysis properties of the alginate–carbohydrate gels were studied. The results indicate that the mechanical properties of “wet” alginate films/casings can be modified by adding various carbohydrates to them. Alginate films with pectin, carrageenan, and modified potato starch had significantly (P < 0.05) greater elongation values than pure alginate films. The alginate–pectin films also had greater (P < 0.05) tensile strengths than the pure alginate films. Alginate films with extracted cellulose, commercial cellulose, and modified potato starch had lower (P < 0.05) puncture force, distance, and work values than the alginate control films. Transmission electron microscopy images showed a very uniform alginate network in the control films. Several large cellulose fibers were visible in the films with extracted cellulose, while the cellulose fibers in the films with commercial cellulose were difficult to distinguish. Despite these apparent differences in cellulose fiber length, the 2 cellulose films had similar puncture and tensile properties.     

Der Energieaufwand in der Reibenstation bei der Kartoffelstärkefabrikation

The Energy Expenditure in the Rasp Station of Potato Starch Production. Three different types of potato rasps being used in Polish Starch Industry were tested: ZT-300 “Spomasz” (Poland). Holthuis (Holland), RU 80-500 Nivoba (Holland). Optimum throughputs depending on energy consumption per one ton of potatoes and disintegration factor were determined. The results confirmed the assumption that increase of throughput decreases electrical energy consumption, however is restricted by disintegration efficiency (factor min. 90%). The latter effects quantity of bound starch on potato pulp and yield of potato starch recovery at the same time. The optimum throughputs for the three rasps were determined.     

Indigestible Starch of P. lunatus Obtained by Pyroconversion: Changes in Physicochemical Properties

Lima bean (Phaseolus lunatus) starch was modified using pyroconversion to produce non‐digestible starch and the functional properties of the pyrodextrinized starches were evaluated. Reaction conditions included: starch/2.2 M HCl ratio (80:1 and 160:1, w/v); temperature (90°C and 110°C) and reaction time (1 and 3 h). “In vitro” indigestible starch and color difference (ΔE) were determined and used as response variables. The optimum product was recovered from native starch treated with a 160:1 starch/HCl ratio, at 90°C for 1 h, which produced modified starches containing 49.5% indigestible starch and ΔE of 18.86. Starch pyrodextrinization decreased the amount of enzymatically available starch through formation of atypical glycosidic bonds that are not digested by the amylases and maltooligosaccharidases in the small intestine of humans. Compared to the P. lunatus native starch, the pyrodextrinized starch exhibited increased paste and gel clarity (52.7%T), solubility (88.7%), and swelling power (26 g water/g starch), a higher gelatinization temperature range (72.5–89.8°C) and lower viscosity. This process can be considered a promising treatment for production of resistant starch (RS) from P. lunatus.     

Rapid Estimation of Potato Tuber Quality by Near‐Infrared Spectroscopy

Starch and protein parameters of potato tubers were estimated by near‐infrared (NIR) spectroscopy measurements of the crude potato mash. Calibration was carried out with a condensed data set of original 1481 individual samples from a varying number of varieties and breeding lines, grown at eight locations over a three‐years period. Validation of the models was performed with an independent data set (n = 133). Starch content of potato tubers was determined with the official under‐water weighting procedure of the EU, and could be predicted with 90% confidence. The NIR model of phosphorus content of starch had a prediction confidence of 53%. Total protein content could be predicted, too (62% confidence), whereas the amount of coagulable protein was not predictable (R² = 0.25). Despite the different qualification levels of the models, guiding to concrete prediction tools or to a very rough estimation graduating from “low” to “high”, the NIR technique enables potato starch processing plants to optimise both potato starch quality and processing efficiency.     

Anisotrope Lichtstreuung durch eine Anhäufung von Stärkekörnern

Anisotropic Light Scattering by a Population of Starch Granules The problem of correlation between the “experimental” scattering diameters calculated using the Stein-Rhodes equation and the observed radii of single starch granules was reexamined for wheat and tapioca starches. The calculated “experimental” scattering diameter was compared with a “theoretical” scattering diameter calculated from an intensity profile which was computed by applying the Stein-Rhodes equation to the population size distribution. The agreement between these two parameters suggests that it is unnecessary to postulate an isotropic region in the centre of the granule.     

MODELING OF PREHEAT TREATMENT OPTIMIZATION APPLIED TO FRESH‐CUT “ROCHA” PEAR

ABSTRACT

Response surface methodology based on a five‐level, three‐variable central composite rotatable design was used for modeling the effects of preheat treatments on fresh‐cut “Rocha” pear quality. Studied variables were time (t: 0–150 min), temperature (T: 20–50C) and posttreatment storage time (St: 0–20 days, 5C). The quality‐affecting parameters including color, firmness, pH, soluble solid content, and total ascorbic acid content were the monitored dependent variables. Results provide reasonable estimation of the impact of preheat treatments on the quality of fresh‐cut “Rocha” pear and its shelf life. The time–temperature range of 33–41C during less than 20 min was selected as the conditions that best provided surface browning control, without impairing other studied quality parameters, with an estimated 8‐day shelf life period. The achieved kinetic changes of polyphenoloxidase, partial reduction in enzyme activity (ca. 23%) and depletion of phenolic content (ca. 11%) could be responsible for the browning control.

PRACTICAL APPLICATIONS

Minimal processing, namely cutting operations, triggers physiological reactions which limit fresh‐cut Rocha pear shelf life. Superficial browning is one of the major concerns to this industry, and new “clean” methodologies aiming at the inhibition of such reaction and maximization of the product shelf life will benefit not only from product marketability but also will respond to the consumers' demand of “chemical free” products. Heat treatments have been used to improve fresh‐cut commodities' browning resistance. The present work evaluated the use of preheat treatments against this physiological disorder during storage. Results will provide an optimized preheat treatment that grants high‐quality fresh‐cut Rocha pear with suitable shelf life.

     

Standardization of Methodology for Chemical Functions in Starch Derivatives. Part 2

The work of Work Group 3, of the International Standards Organization Technical Committee 93 (ISO/TC 93/WG3), concerning the determination of functional groups in starch derivatives, has been progressed. The Netherlands Normalisatie Instituut (NNI) is the secretariat and Part I of this paper outlined the total work programme and reported the finalised work on acetyl and carboxyl functions. Following modifications, the available methodology for the adipyl function was improved, and has been validated. The methodology for the determination of the carboxymethyl function by titration of the carboxyl group, has also been refined and validated by collaborative testing. Draft International Standards have been made of these two methods so that they can be voted on by members of ISO and the European Committee for Standardization (CEN) in a parallel process. Work on the hydroxypropyl function has not yet come to a successful conclusion. A colorimetric method showed poor reproducibility, due probably to its empirical nature; little support was found for gas chromatographic methods. However, the use of proton NMR might yield a satisfactory means. While all members of the Work Group are not equipped with the required instrument, a preliminary study will be done with the help of other laboratories.     

Some Physico-chemical Properties of Fermented Cassava Starch („Polvilho Azedo”︁)

This work intended to give some contribution to the study of the “polvilho azedo”, a fermented cassava starch that is obtained by a rudimentary and empirical process, and to make it better known. A comparative study showed that in addition to giving the characteristic flavor to the cassava starch, the fermentation causes some changes on its physico-chemical properties: The fermented starch is more soluble and easily swells in water, and when its aqueous suspension is heated, the paste formed is less viscous than that of the non-fermented cassava starch.     

Physiochemical and Rheological Characterization of Sorghum Starch

Starch was isolated from the seeds of 3 sorghum cultivars and compared with commercial wheat starch. The amylose content of sorghum starches was in the range of 22.0–27.8%. Sorghum starches had less total lipids than wheat starch (1.66%) but there was no difference between sorghum Milo and Sorghum “100”. The water binding capacity of sorghum Dabar did not differ from that of wheat (100%) whereas differences in swelling power were observed, over a range of temperatures, between wheat and sorghum starches except for Sorghum “100” at 70°C. Sorghum starches showed single-step viscoamylographic curves with pronounced pasting peaks, good pasting stability and good set-back on cooling.     

Zur Mikroskopie der Stärkekörner von gekeimten Kartoffeln

On the Microscopy of Starch Granules of Germinated Potatoes. Microscopic examinations of normally germinated as well as germinated and dried potato tubers and of the germs as such showed that the generalized assertion of D. Grebel, according to which a “melting” should be characteristical for the fermentative degradation (germination) of starch, cannot be confirmed. Indeed, the described melting phenomena occurred with single starch granules, the majority of the fermentatively deformed starch granules, however, showed the typical changes (channel formation) as they are to be seen with starch granules of cereals. With partially dried potato tubers and their germs the starch granules showed changes like those occurring with curcuma starch. Factors that are responsible for this symptom are being discussed.     

Starch Lipids: A Reappraisal

It is proposed that lipids on the surface of starch granules should be called “starch surface lipids”, and that those inside the granules should be called “internal starch lipids”. Starch surface lipids appear to be derived from the “non-starch lipids” which are either free or bound to proteins in the starch-bearing tissues. In cereals the internal starch lipids are exclusively monoacyl lipids, and they are quite different in composition from the starch surface lipids and non-starch lipids. In some recent publications lipids purporting to be internal starch lipids evidently include substantial quantities of non-starch or surface lipids.     

Wirtschaftliche Bewertung der direkten enzymatischen Herstellung von Stärkeverzuckerungsprodukten aus trocken vermahlenem Mais

Economical Evaluation of the Direct Enzymatic Manufacturing of Starch Saccharification Products from Dry-milled Maize. Dry degermed maize can be used as starting material for the production of glucose syrups, glucose sugar, and dextrose monohydrate. The conversion of starch, contained in maize, into soluble carbohydrates takes place by means of amylases, which act specifically and selectively on starch, while protein and cellulose are not effected. Dry degermed maize can be manufactured at a lower cost than an equivalent quantity of refined starch. Therefore it is possible to produce hydrolysis products at a lower cost price, with maize flour as raw material. The investment and operating costs for a “wet milling-traditional hydrolysis plant” are compared with the corresponding costs for a “dry milling-enzymatic hydrolysis plant”.     

Impact of Annealing on the Physicochemical Properties of Unfermented Cassava Starch (“Polvilho Doce”)

Unfermented cassava starch (“polvilho doce”) was subject to annealing treatment at 50°C for 24, 48, 96, 120, 168 and 192 h, in 1:5 starch to water ratio. The annealing treatment changed the internal structure of “polvilho doce” at increasing treatment time. Peak viscosities decreased significantly, denoting that there was a decrease in leaching of amylose from the granules. The pasting temperatures were increased, setback and breakdown were reduced while hold and final viscosities increased, showing an improvement of the stability of the paste. Swelling power and solubility were reduced at all temperatures and the solubility at 55°C was zero after 120 h of treatment. The DSC data for T_o, T_p, T_c and ΔH increased and the gelatinization range was narrowed. The X‐ray diffractograms changed from C_A to A pattern (samples annealed for 48, 96, 120, 168 and 192 h), denoting an increase in organization of double helices of amylopectin. Annealing imparts to the samples some waxy starches characteristics which can be very useful in the food industry.     

THE BREWING POTENTIAL OF “ACHA” (DIGITARIA EXILIS) MALT COMPARED WITH PEARL MILLET (PENNISETUM TYPHOIDES) MALTS AND SORGHUM (SORGHUM BICOLOR) MALTS

The malting and brewing characteristics of millets (Pennisetum typhoides and Digitaria exilis) and sorghum (Sorghum bicolor) were compared. Diastase, α-amylase, amyloglucosidase and proteases increased with malting time and the increase was associated with the modification. Development of hydrolytic enzymes was significantly higher in pearl millet and Digitaria exilis (“acha”) than in sorghum at P ≥ 0.01. The major starch degrading enzyme in the three varieties of pearl millet (SE composite, SE.13 and SE 2124) was α-amylase. On the other hand, β-amylase was the major starch degrading enzyme in “acha” (Digitaria exilis) which is similar to the pattern in barley. Gibberellic acid had a stimulating effect on the diastatic activity of pearl millets, Digitaria exilis (“acha”) and sorghum (KSV-4), but inhibited the diastatic activities of sorghum (Farafara). Gibbereltic acid inhibited the proteolytic activities in all the pearl millet varieties, Digitaria exilis and sorghum varieties. Potassium bromate had little or no effect in the reduction of malting losses. Although “acha” (Digitaria exilis) had a high β-amylase content, a high malting loss makes it uneconomical to brew with “acha” mart. A blend of “acha” malt with pearl millet malt or sorghum malt (composite malt) will produce a malt of the same profile as barley malt and this will enhance the quality of sorghum and pearl millet malt during the mashing process. Wort quality of all the samples was suitable for brewing conventional beer.