Loss Of Starch Research Articles

Effect of sequential abrasion on starch composition of five cereals for ethanol fermentation

Five cereals were abraded successively on a Satake abrasive test mill to enhance the starch contents of the pearled grains to improve fermentation efficiency of fuel ethanol plants. Tempering the cereals to 12.5% and 15.0% moisture had no consistent effects on rates of grain mass removal by abrasion but final starch losses to the abraded fines could be minimized by optimizing grain moisture content. Increasing abrasion time from 10 to 55s increased the average grain mass removal from 3.5 to 19.5% in four hulless cereals but 70s of abrasion was needed to remove 32.6% of two-row barley to obtain a comparable starch content in the pearled grain. On a dry basis, the pearled grain starch levels were: Canadian Prairie Spring (CPS) red wheat (73.4%); CPS white wheat (72.2%); two-row barley (71.0%); fall rye (70.4%); and triticale (69.1%), which represented, on average, a 12% increase in starch content over those of the original grains. Ethanol yields per tonne of fermentation feedstock were increased by 6.5–22.5% as a result of abrasion, which would substantially increase ethanol plant throughput and grain fermentability.

Effects of Aminoethoxyvinylglycine (AVG) on Preharvest Fruit Drop and Maturity of ‘Delicious’ Apples

Abstract Aminoethoxyvinylglycine (AVG) applied 2 to 6 weeks before the optimum harvest date dramatically reduced preharvest drop of ‘Delicious’ apples (Malus domestica Borkh). The loss of fruit firmness, starch, and water core was reduced by AVG sprays particularly when harvest was delayed beyond the optimum harvest date. Color development and soluble solids concentration (SSC) generally was unaffected. Equivalent dilute airblast concentration (EDAC) of 44 mg·L−1 AVG was no more effective than a standard rate of napthalene acetic acid (NAA), but a rate of 44 mg·L−1 AVG EDAC + a silicone surfactant ABG 7011 or 88 mg·L−1 AVG EDAC was more effective than NAA. When fruit were left on the tree for periods of 3 to 5 weeks after the optimum harvest date, NAA enhanced softening and loss of starch and increased water core of ‘Delicious’. Soluble solids and red color generally were unchanged by NAA. Ethephon sprays hastened the rate of fruit drop. When NAA was tank mixed with ethephon, it delayed fruit drop caused ...

Effects of Aminoethoxyvinylglycine (AVG) on Preharvest Fruit Drop, Maturity, and Cracking of Several Apple Cultivars

Abstract Aminoethoxyvinylglycine (AVG) applied 2 to 6 weeks before the optimum harvest date dramatically reduced preharvest drop of several apple cultivars (Malus domestica Borkh). AVG sprays reduced the loss of fruit firmness and starch particularly in harvests after the optimum harvest date. The development of water core was delayed in ‘York’, and maturity cracking was delayed or prevented in ‘Rome’ and ‘Golden Delicious’ by AVG. Color development was delayed by AVG for summer cultivars, ‘Redfree’ and ‘Gala’, and for ‘Golden Delicious’, but did not have an influence on red color of ‘Rome’ or ‘York’. Soluble solids concentration (SSC) was generally unaffected. Equivalent dilute airblast concentration (EDAC) of AVG at 44 mg·L−l was more effective than a standard rate of NAA for control of fruit drop for ‘Golden Delicious’. For ‘Law Rome’, an AVG rate of 66 mg·L−1 was more effective than NAA, but for ‘York’ these rates gave similar control of drop as NAA. AVG at 132 mg·L−1 ED AC and above was more effectiv...

Biodegradation of starch-polyethylene films in soil and by microbial cultures

Among the starch-containing low density polyethylene films tested for biodegradation, films containing 30% starch showed maximum biodegradation leading to a loss of 6.3% in weight and 84.5% starch upon burial in a soil–compost mixture for 48weeks. Biodegradation of this film was accelerated by incubation with an acclimatized culture in a shake-flask showing 11.2% and 68.9% loss of weight and starch respectively, after only 6 weeks. FTIR and 13C NMR analysis revealed that the loss of starch in biodegraded films is accompanied by structural changes in polyethylene in terms of reduction in the peak area of polyethylene backbone and short chain branches.

AVG Effects on Preharvest Apple Fruit Drop and Maturity in Virginia

AVG applied 2 to 6 weeks before the optimum harvest date for several cultivars dramatically reduced pre-harvest fruit drop. The loss of fruit firmness and starch loss after the optimum harvest date was reduced by AVG sprays. The development of watercore in `Starkrimson Delicious' and `York' and maturity cracking in `Rome' and `Golden Delicious' were delayed and/or prevented by AVG. Color development was slightly delayed for most red cultivars and `Golden Delicious'. Soluble solids concentration was generally unchanged. Airblast applications of 123 g·ha–1 AVG was no more effective than a standard rate of NAA (28 to 56 g·ha–1), but rates of 248 g·ha–1 AVG and above were more effective than NAA for most cultivars. When fruit were left on the tree for periods of 3 to 5 weeks after the optimum harvest date, NAA hastened the loss of fruit firmness and starch and NAA increased watercore of `Delicious' and maturity cracking of `Golden Delicious' and `Law Rome'. Soluble solids and red color were generally unaffected by NAA. Ethephon sprays hastened the rate of fruit drop. When NAA was tank mixed with ethephon, NAA delayed fruit drop caused by ethephon, but AVG did not. The use of superior oil or Regulaid surfactant did not affect NAA or AVG responses; however, the silicone surfactant Silwet L-77, in one experiment, promoted the effectiveness of AVG. Tank mixing NAA or AVG with pesticides (Guthion + Lannate + Captan) did not affect the responses of AVG or NAA on fruit drop.

Contribution of fiber and resistant starch to metabolizable energy

Recommendations made to increase complex carbohydrate and fiber intake in the United States may result in energy loss from increased fecal losses of starch, protein, and fat. The type of fiber or starch and the amount consumed affect digestion of the carbohydrate and interactions with other nutrients. On average, 8.4 kJ (2 kcal) digestible energy/g is available from up to 70 g poorly digested carbohydrate/d. Undigested fiber and starch are important substrates for colon bacteria and are fermented to short-chain fatty acids, hydrogen, and methane. Hydrogen and methane excreted through the lungs have been used as indicators of colonic fermentation. Fermentation appears to contribute significant digestible energy when > 20 g poorly digested carbohydrate/d is consumed.

Mobilization of Starch after Submergence of Air‐Grown Rice Coleoptiles. Implications for Growth and Gravitropism

AbstractSubmergence of air‐grown rice seedlings (Oryza sativa L. var. Sasanishiki) induces elongation of the coleoptile. We investigated whether rapid underwater extension is associated with a loss of starch. After 1 d of submergence the starch content was reduced by 70%. This loss of reserve carbohydrate was accompanied by a 38% increase in the concentration of glucose in the cell sap of the coleoptiles. The submerged (starch‐depleted) coleoptiles had a slower negative gravitropism than the air‐grown controls, although the rate of elongation in the horizontal position was not impaired. We conclude that the submergence‐induced mobilization of starch provides substrates and osmotica for the rapidly growing cells. In addition, our results indicate that a full complement of starch is necessary for normal gravitropism in the rice coleoptile.

RESEARCH PRIORITIES FOR SAGO PALM DEVELOPMENT IN INDONESIA AND SARAWAK: AN AGENDA FOR RESEARCH

During travelling through Indonesia and Sarawak the latest developments in sago palm cultivation have been evaluated in a technical sense. In the coming two decades quite an increase in the production of sago palm starch is to be expected through both new plantings and exploitation of natural stands. The agronomy for this development is based nearly solely on observation of small scale farmers' practices. Research lags dangerously behind, although more so in Indonesia than in Sarawak. Three groups of research questions have been identified. The most pressing is (1) the necessity to apply fertilizer for a sustained high yield. This is of even more importance on the notoriously poor deep peat soils than it already is on mineral soils. Without a solution to this problem the large scale cultivation of the crop is at a dead end. A good second in importance is (2) how to obtain optimum starch yields from trunks per unit of time and area, combined with the reduction of starch losses in processing. On the somewhat longer run should be studied (3) the taxonomy of the sago palm, in relation to its growth pattern. For each group of research questions holds that research personnel working at it should be experienced with or at least be well acquainted with the sago palm. Two pioneer-operations are important to obtain part of the necessary practical experience: (1) the large scale deep peat plantings by Estet Pelita, especially the first close to Mukah in Sarawak; (2) the exploitation by INHUTANI I of a natural stand on mineral soils on Halmahera in the Northern Molucca's. In Sarawak, Estet Pelita just started with a research programme. Agronomic research is developed there also mainly on the deep peat experiment station of the Research Branch of the Sarawak Department of Agriculture at Dalat, close to Mukah. Small collections of genetic material have been started in this experiment station and in Makariki on Seram in the Molucca's. The small model-planting on clay soils run by B.P.P. Teknologi close to Bogor, West Java aims at solving some practical questions. There still is a lack of manpower, trained in sago palm growth and development. Training of sago palm agronomists should be a joint concern of the countries involved in the development.

High Relative Humidity after Ethylene Gassing is Important to Banana Fruit Quality

Bananas were held at 18C in all possible combinations of 65%, 75%, or 95% relative humidity (RH) before and after gassing with ethylene. Peel color, fruit firmness, starch loss, compression injury to peel and pulp, and overall peel scarring were measured. Peels were greener and the fruit were slightly firmer when fruit were held in the higher humidity combinations, particularly when the humidity was high after gassing with ethylene. Starch loss was not different among humidity treatments. Overall peel scarring was about twice as severe with 65% RH compared to 95% RH during the ripening phase. Low humidity before ethylene gassing had little effect on overall scarring. There were some instances where humidity had a significant effect on compression injury; high humidity caused less injury, but the effect was inconsistent.

A carbon-13 method for evaluating degradation of starch-based polymers

A new method for evaluating biodegradability of starch-based and certain other polymer blends uses the pre- and postexposure stable carbon isotope composition of material coupled with weight loss data to determine which components have degraded. The naturally occurring stable isotope of carbon.13C, is enriched in corn starch (δ13C, approx. −11‰) compared to petroleum-derived synthetic polymers (δ13C, approx. −32‰). Results on starch-synthetic polymer blends indicate that the δ13C signatures of these blends are near-linear mixtures of their component δ13C. Values of a δ13C for starch-synthetic polymer blends exposed to biologically active laboratory soil and artificial seawater conditions are depleted in13C compared to unexposed samples, suggesting loss of the starch component. Combined with weight loss data for the exposed samples, the δ13C values are statistically consistent with models requiring loss of the soluble component glycerin, followed by loss of starch, then petrochemical polymer, or simultaneous loss of starch and petrochemical polymer. Replicate δ13C analyses of starch-synthetic polymer blends increase the statistical power of this relatively inexpensive, accessible technique to discriminate between degrading components.

The effect of varying levels of Gamborg's B5 salts and temperature on the accumulation of starch and hyoscyamine in batch cultures of transformed roots of Datura stramonium

The partitioning of carbon between reserve polysaccharide and alkaloid secondary products was investigated in batch cultures of transformed roots of Datura stramonium grown in media in which the carbon substrate concentration was held constant and the level of mineral nutrients was varied. The growth and accumulation of starch and hyoscyamine was examined in roots grown at temperatures of 20°C, 25°C or 30°C in media containing 5% sucrose and levels of mineral nutrients varying from 1/4 to twice the standard level of Gamborg's B5 salts. The dry matter content was highest (up to 15% w/w) in roots grown at either 20°C or 25°C in medium of the lowest ionic strenth (1/4 B5 salts) and decreased as the ionic strength was raised (down to 7% w/w with 2 B5 salts). Up to half of this decrease could be accounted for by loss of starch from the roots. At 20°C and 25°C, the starch content of the roots grown in medium of the lowest ionic strength (1/4 B5) was 40 mg g-1 and 22 mg g-1 fresh weight respectively but decreased to less than 1 mg g-1 weight at either temperature when the ionic strength of the medium was raised to 2 B5. At 30°C, starch accumulation was severely inhibited in all media. In contrast, varying either the temperature or the ionic strength of the medium had only a small effect on hyoscyamine accumulation which remained at between 0.4–0.6 mg g-1 fresh weight. Although increases in the level of mineral salts had little effect on the hyoscyamine content of the roots, total yields however, increased due to stimulation of growth. Time course experiments showed that cultures grown at either 20°C or 25°C continued to accumulate both starch and hyoscyamine into late stationary phase.

The effect of field drying on the non‐structural carbohydrate composition in vetch hay

AbstractCommon vetch (Vicia sativa L) was harvested and allowed to dry in the open air. The composition of fresh forage in non‐structural carbohydrates varied markedly between years, the contents of sugars and starch in both leaves and stems being much higher in 1990‐91 than 1991‐92. Field drying produced a significant decrease in the amounts of these carbohydrates. The total losses of sugars and starch in hay, expressed as losses of dry matter, ranged from 28 to 15 g kg‐1, depending on the year.

Effects of intensive microbial metabolism on starch-filled polyethylene films in controlled compositing windows.

Low density (LDPE) and high density (HDPE) polyethylene films filled with starch up to a maximum level of 20% by weight were tested for biodegradation under different environmental conditions. Composting windrows consisting of various putrescible waste and assembled for controlled biostabilization management under static conditions were used. The physical and chemical deterioration of the polyethylene-starch films exposed to a controlled composting environment were recorded and analyzed with respect to the different composting evolution and were compared with the data collected in pure culture systems and in bench scale tests simulating an aerobic biostabilization process. Evidences are presented on the partial removal of starch from the different films as a consequence of massive surface colonization by various microorganisms. Loss of starch is accompanied by a small but significant drop in the average molecular weight and decrement in mechanical strength. In the case of a composting trial experiencing prolonged severe temperature conditions, a small but spectroscopically detectable oxidation of the polyethylene matrix was also observed. Efficiency of the controlled composting systems can be claimed in assessing reproducible conditions in an accelerated biostabilization of putrescible matter and hence versatility in the evaluation of the degradation of plastic manufacts.

Weathering of starch–polyethylene composite films in the marine environment

AbstractPolyethylene and starch–polyethylene composite films were exposed outdoors in the straw‐line of a marsh and in sea water on flow‐through seatables in the laboratory. The deterioration of these films following exposure was measured by determining changes in tensile properties, weight loss, starch loss, and carbonyl content of the sheet plastic films. Low rates of deterioration were observed for control and starch–polyethylene composite films submerged in sea water. In contrast, both starch–polyethylene composite and control polyethylene films rapidly deteriorated during exposure in the strawline of a marsh. Differences in the observed rate of deterioration of the films placed in the exposure sites is attributed primarily to photodegradation of the films placed in the strawline of a marsh. © 1993 John Wiley & Sons, Inc.

Loss of Starch and Increase of α-Amylase Activity in Leaves of Flooded Tobacco Plants

Loss of Starch and Increase of α-Amylase Activity in Leaves of Flooded Tobacco Plants

Deterioration of Starch-Plastic Composites in the Environment

The rate and extent of deterioration of starch-plastic composite and control plastic films were determined for films weathered in landfill, compost, soil, seawater and the strawline of a marsh. Films were placed in the exposure sites during the Spring of 1989 and sampled over a 28 month period. Environmental conditions at each exposure site were determined during each sampling event. Following placement, deterioration of the starch-plastic composite and control plastic films was determined by measuring changes in tensile properties, weight, starch content and morphology. Results showed that the rate of degradation of the starch-plastic composite films varied when weathered in different environmental settings. Rapid degradation and fragmentation of the films in the strawline of a marsh was primarily attributed to photodegradation. Lesser degradation was measured for films placed in compost, landfill, soil and seawater. Starch loss was measured for starch-plastic composite films in each of the exposure sites. The rate of starch loss decreased with time. With the exception of films in the strawline, the starch-based films did not fragment or lose mass during two years of weathering. Although starch-plastic composite films are designed to deteriorate primarily through the actions of microorganisms, deterioration of these films is a result of the interaction of biological, chemical and physical processes.

Degradation of starch modified polyethylene bags in a compost field study

The degradation of commercially available leaf bags made of polyethylene compounded with ECOSTAR PLUS®, a starch based additive, was determined after exposure to a passive composting environment during the summer of 1990. The bags were filled with partially composted leaves and yard waste. Half of the bags were buried inside and half on the surface of the pile. One bag from each group plus a control was removed at 14, 28, 42 and 49 days of exposure. The tensile properties, FTIR and UV-vis spectra, differential scanning calorimetry and light microscopy determinations were performed on these samples. The surface bags showed oxidation, loss of starch, lower melting point and embrittleness after 14 days. The buried bags had lower melting points at 14 days and showed oxidation at 28 and 49 days. These results indicate that exposure to daylight had a marked effect in the degradation of the surface bags while the degradation of buried bags may involve other processes.

Decay of date palm wood by white-rot and brown-rot fungi

Wood from trunks of Canary Island date palm (Phoenix canariensis) was decayed for 12 weeks with white-rot fungi (Ganoderma colossum, G. zonatum, Phanerochaete chrysosporium, Scytinostroma galactinum, or Trametes versicolor) or brown-rot fungi (Wolfiporia cocos, Gloeophyllum trabeum, or Fomitopsis pinicola). Using the vermiculite-block assay, white-rot fungi caused significantly more weight loss (63%) than brown-rot fungi (32%). Of the white-rot fungi, G. colossum caused the greatest weight loss (81%), while S. galactinum caused the least (36%). In contrast, weight loss caused by the brown-rot fungi was similar. Chemical analyses indicated that both white-rot and brown-rot fungi caused losses of starch, holocellulose, and lignin. White-rot fungi, however, removed greater amounts of lignin than the brown-rot fungi with three species, S. galactinum, P. chrysosporium, and G. zonatum, causing selective delignification. Scanning and transmission electron microscopy showed that phloem and parenchyma cells were more susceptible to decay than xylem and fiber cells. Starch grains were degraded by all fungi and were nearly removed in wood decayed by G. colossum. In wood decayed by white-rot fungi, cell walls were eroded and middle lamellae were degraded. Selective delignification was observed in fibers adjacent to vascular tissue in wood decayed by the three white-rot fungi. In wood decayed by brown-rot fungi, walls of ground parenchyma and vascular bundle cells were swollen and fragmented when physically disrupted. In wood decayed by F. pinicola, some cell walls were nearly disintegrated. Key words: selective delignification, simultaneous decay, ultrastructure.

Distribution and Evolution of Forms and Types of Sieve-element Plastids in the Dicotyledons

Sieve-element plastids may contain any combination of protein crystals (c), protein filaments (f), and starch grains (s), or none of these. All structurally distinct combinations (=forms) possible (s, cs, cfs, c, cf, fs, f, o) are recorded among the 2100 dicotyledons investigated so far with the transmission electron microscope (representing 381 of more than 460 families described). The six forms that include c and/or f define the P-type and are found in some 620 species, mainly confined to Magnolianae, Caryophyllanae, Vitanae, and Rutanae (Fabales, Linales, Rhizophorales). A detailed family-by-family analysis and quantitative form-by-form comparison suggests that form-Ss plastids give rise to all other forms. Based on a logic model connecting all forms via one-step-alterations (loss or gain of starch, protein crystals, or filaments), the distribution of P-type plastids within dicotyledons, their interconnection, and their relationships to the S-type taxa are discussed. Due to the diversity of sieve-element plastids found within one taxon, the Magnolianae (P- and S-type) are held to be a center of P-type evolution and more primitive than Caryophyllanae (P-type, only) or other superorders. The significance of sieve-element plastid data to the shaping of some of the higher dicotyledon taxa is discussed.

Biodegradability of Polyhydroxybutyrate(co‐hydroxyvalerate) and Starch‐Incorporated Polyethylene Plastic Films in Soils

AbstractGiven the extremely low rates of microbial decomposition of most common plastics, the manufacture of biodegradable plastics is of interest as a means of managing the solid waste stream, as well as for specialty applications in pharmaceuticals and agriculture. In order to evaluate the biodegradability of several plastics commercially developed for enhanced biodegradability, plastic films of two types—(i) polyhydroxybutyrate copolymerized with hydroxyvalerate (PHBV) and (ii) low density polyethylene (LDPE) incorporated with a starch filler—were incubated for 44 d under moist, aerobic conditions in two soils, an acid sand and a calcareous sandy loam. Biodegradability of the plastics was evaluated based on evolution of CO2‐C upon incubation and by microscopic examination after 44‐and 150‐d incubation under the same conditions. Biodegradation of polyhydroxybutyrate films ranged from 5% to near complete biodegradation during the 44‐d incubation, depending on soil type, film thickness, and the nature of chemical additives to the polymer. Granules of embedded starch exposed at the surface of starch‐incorporated polyethylene films were degraded within 14 d, after which no further biodegradation could be detected; no gross deformations of the plastic film were associated with the loss of surface starch.