Presoaking Treatment Research Articles

Physicochemical properties and cooking quality of four new cultivars of Nigerian cowpea (Vigna unguiculata L walp)

AbstractFour new cowpea cultivars (IT81D‐699, IT82E‐18, IT84S‐2246‐4 and TVx 3236) were evaluated for their physicochemical properties and cooking quality. The four cultivars fell into two categories (rough and smooth) according to testa texture, and varied in seed dimensions and weights with IT81D‐699 and IT84S‐2246‐4 having smaller seed volume than IT82E‐18 and TVx 3236. Leached solids, swelling capacity and seed coat percentage were within a range of 0·33–0·94 g per 100g, 77·0–123·5 g per 100 g and 5·6–15·7% w/w of dry beans respectively. The total polyphenol content of the brown or cream‐coloured beans were similar (1·53–1·96 mg g−1) but higher than the amount (1·03 mg g−1) found in the white bean. Cooking time varied between 29 and 37 min and was reduced by about 21% following a presoaking treatment in water for 12 h at room temperature (28 °C). Cooking time was significantly positively correlated (P < 0·05) with seed weight (r = 0·82) and seed volume (r = 0·75). Water absorption was not related to cooking time, and was much lower for the cultivar with larger seeds. No significant difference in hardness was found between unsoaked beans cooked for 30 min and soaked beans cooked for 10 min, suggesting that cookability for all cultivars was improved through soaking.

Effect of Gibberellic Acid on Seedling Growth and Carbohydrate Metabolism During Germination of Rice (Oryza sativa L. var. GR‐3) Under Saline Condition

AbstractInteractive effect of NaCl salinity and gibberellic acid (GA3) on seedling growth and carbohydrate metabolism of rice was studied for five days. NaCl reduced the embryo axis growth and the rate of hydrolysis of starch in the endosperm. Parallel to this reduced rate of reserve carbohydrate mobilization, a decreased activity of α‐amylase, β‐amylase, maltase and invertase was also found in the endosperm of sale stressed seeds. Presoaking treatment of seeds with GA3 (10 mg l−1), however, increased the growth of seedlings and enhanced the hydrolysis of starch as well as the activities of said enzymes. Electrophoretic analysis revealed that NaCl inhibits the synthesis of amylase isozymes which, in turn, reversed considerably by GA3 application.

Substrate presoaking effect on immobilization of protease on pig bone particles

When pig bone (PB) particles and other support materials were presoaked in casein solution and crosslinked with glutaraldehyde, the activity of immobilized protease, was two or more times greater than those of the proteases immobilized on non-treated supports. Chitopearl was an exception. The highest activity, 25000 U/g-support, was obtained with the presoaked PB particles. The effect of presoaking the supports in the substrate solution on the immobilized protease was also observed with other protein substrates. The effect of the presoaking treatment increased with an increase in the molecular weight of the protein. The increase in the activity of the immobilized enzyme was due to increases in both the amount of adsorbed protease and specific activity. Furthermore, the stability of protease immobilized on PB was remarkably improved by transforming the PB particles into a sheet.

Improvement in cooking quality of horse gram (Dolichos biflorus) by pre-soaking treatment with salt solution

Soaking of horse gram (Dolichos biflorus) in a solution of 1.5% NaHCO3, 0.5% Na2CO3, and 0.75% citric acid for 12 h was found to be effective in reducing cooking time from 145 to 27 min. The treatment improved protein digestibility of cooked horse gram from 69 to 78%. Horse gram cooked after pre-treatment with soak solution had 35% less amount of polyphenols than that in untreated cooked samples. The suitability of this treatment for reducing cooking time of several other legumes was evaluated.

Studies on the processing and properties of soymilk. II. Effect of processing conditions on the trypsin inhibitor activity and the digestibility in vitro of proteins in various soymilk preparations.

AbstractSoymilks prepared from beans which had been soaked either in water or 0.4 M sodium carbonate solution for 24 h as a pretreatment were subjected to heat treatment under different conditions for varying lengths of time, to destroy the trypsin inhibitor activity. The rate of inactivation oftrypsia inhibitor in soy milks prepared from carbonate presoaked beans was faster than that of the water presoaked preparation when processed at 98°C and this effect was primarily associated with the change that occurred in the pH of the former system; The effect of alkaline pH's at 98°C on the inactivation of trypsin inhibitor was examined and it was found that the rate of inactivation was changed from zero order at pff 6.8 to first‐order kinetics at pH 9.9. Regression equation relating pH of the system and time of heating at 98°C for 100% destruction of the inhibitor activity is presented. This effect of pretreatment was eliminated when both milks were processed at 115°C in cans because of the constancy of pH under these conditions. The influence of heat processing conditions on the enzymic digestibility of proteins in both soymilks was also studied. The pepsin digestion showed no significant differences between milks prepared from the water and the carbonate presoaked soybeans, and was highest in milks which had not been heat treated. With trypsin the digestibility increased with the degree of heal treatment up to the point where the trypsin inhibitor was destroyed, after which further heating resulted in lower digestibilities. A 19% increase in digestibility by trypsin was observed in the milk prepared from carbonate presoaked beans when compared with that from water presoaked beans and after both milks had been heated at 98°C for just sufficient time to destroy the trypsin inhibitor. When the milk prepared from water presoaked beans was autoclaved at 115°C to the same end point, its digestibility increased but it was still about 6% lower than that of the milk prepared by alkali presoaking method and processed at 98°C. The digestibility of casein using pepsin under the conditions used was lower than that of both soymilks. When trypsin was used the digestibility of casein was approximately the same as that of the adequately processed soymilk from carbonate presoaked soybeans or the autoclavtd soymilk from water presoaked beans. Other effects of using a carbonate presoaking treatment far the production of soymilk have also been discussed.

Studies on the processing and properties of soymilk. I. Effect of preprocessing conditions on the flavour and compositions of soymilks.

AbstractThe effect of presoaking soyabeans in solutions of various chemicals on the reduction of beany flavour in soymilk was investigated. Of the chemicals used, sodium carbonate and sodium hydroxide had a significant effect on the reduction of beany flavour in soymilk. Sodium carbonate soaking at 0.4 M concentration for 18‐24 h was significantly better than any other presoak treatment. The activity of lipoxidase as a major source of beany flavour in soymilk is questioned. Soymilk prepared from beans presoaked in carbonate contained more protein and had a higher viscosity than milks prepared from beans presoaked in water or sodium hydroxide. Beans presoaked in carbonate were easier to process than the other two. There was no significant difference in the amino acid pattern of the proteins in the soymilks prepared by the three methods.

Effects of Seed Age and Preplanting Seed Treatment on Seedling Response in Crested Wheatgrass1

Seed lots of Nordan crested wheatgrass, Agropyron desertorum (Fisch. ex Link) Schult., of six ages were subjected to presoaking treatments on moist blotter paper, for periods ranging from 40 to 90 hr at 17.2 C, prior to greenhouse planting in soil. Seeds given preplanting treatments, and planted wet, produced seedlings which emerged ahead of those from untreated seeds, the hours of advantage in direct relation to the length of pretreatmerit, but drying before planting reduced the advantage. At 4 days after planting, pretreated seeds produced seedlings with longer roots and shoots than those from untreated seeds. Older seeds required more tinie to produce seedlings but the advantage from treatment was not altered by age of seed.

Factors Affecting Spore Germination of Volvariella volvacea

AbstractEnvironmental factors affecting basidiospore germination were studied with Volvariella volvacea, the edible straw mushroom which is common in South East Asia. A relatively mild heal shock is necessary for spore germination. The spores give best germination at 40°C although early hyphal growth is better at 35°C the germination of spores is affected by temperature. pH. a presoaking treatment and spore density. Higher pH supports more germination but seems unfavourable for early mycelial growth. Presoaking treatment in phosphate buffer solution or distilled water also stimulates germination markedly.

Studies on the Hard Seed of Milk Vetch (Astragalus sinicus L.) : X. The cause of the impermeability of hard seed in milk vetch.

The treatment of seeds with four kinds of carbohydrase, four kinds of acid and its corresponding ammonium salt, ethyl ether and chloroform was carried out in order to clarify the cause of the impermeability, especially the substance concerned in it. The results obtained are as follows. 1) When yet the swelled seeds which were nearly ripe, were pretreated by soaking in a 1 per cent pectinase solution for 2 hours, the hard seed content decreased from 64.8 per cent to 8.3 per cent; and in the same pretreatment for 4 hours, the content decreased to 4.3 per cent; and in the same pretreatment for more than 8 hours, the hard seed content was not found at all. This fact indicates that pectinase prevents the hardening of seeds. However, this preventive effect was not found in cellulase, α-and β-amylase using the same pretreatment. 2) A remarkable preventive effect was found in the presoaking treatment, using the same seeds in 0.5 per cent oxalic acid and 0.5 per cent ammonium oxalate solution for 1 hour respectively: the hard seed content was decreased from 56.8 per cent to 0.8 per cent. When the same pretreatment was continued for 2 hours, the content was decreased to 0.5 per cent; and in the same pretreatment for more than 4 hours, the hard seed content was not found at all. If the treatment was prolonged, some decrease of hard seed content was also fouud in the presoaking treatment using the following combinations: 0.5 per cent citric acid and ammonium citrate; acetic acid and ammonium acetate; and hydrochloric acid and ammonium chloride. 3) The effectiveness in breaking hard-coatedness of a 1 per cent pectinase solution, and of a 0.5 per cent oxalic acid and ammonium oxalate, was not found in the case of strong hard seeds which remain hard for 51 days and 100 days respectively after placing on the seed-bed. 4) The soaking treatment with ethyl ether and chloroform gave no indications of being effective in the breaking of hard-coatedness, although it did show signs of effectiveness in the promotion of softening of seeds and germination. 5) From the results obtained, it was concluded that the pectic substances, presumably in the form of pectates, in the strophiole and palisade layers were involved in causing the impermeability of seeds, and that the impermeability was not caused by cuticula, though the cuticula controlled the velocity of seed-swelling and germination.

Influence of soil moisture content on germination and emergence of seeds

This study was designed to clarify the relations of germination and emergence of several kinds of seeds to moisture content of soils, with special reference to their moisture constants and moisture supplying capacities.Seeds were planted in the soils having different moisture contents in the depth of one cm from the surface, and numbers of emerged seeds were counted daily. After the final count, seeds remaining in the soil were exposed and number of germinated seeds were counted. Physical properties of soils used were shown in Table 1.1. Minimum moisture content allowing germination of radish, rape, and sunflower seeds was close to P. W. P. (permanent wilting percentage) in the fine sandy clay loam (alluvial soil) and the fine sandy loam (volcanic ash soil), but was higher than P. W. P. in the coarse sand (river sand). Minimum moisture content allowing emergence of these seeds was a little higher than that for germination (Fig. 1).Critical moisture levels for carrot seed were higher than those for other seeds (Fig. 1). This may be due to the lower moisture absorbing power of carrot seed than that of other seeds (Table 3).2. Average number of days required for emergence of each seed was found to be almost the same in the range down to a certain critical moisture content of the soil, below which number of days increased with the decrease of moisture content. This critical point was close to the minimum capillary moisture content in each soil (Fig. 4, Table 5).3. Pre-soaking treatment decreased minimum moisture content allowing germination and emergence of pea seed, but had little effect to tomato seed, which was much smaller in size than pea seed (Fig. 5).4. Basing on the above mentioned results, it may be concluded that minimum moisture content allowing germination or emergence of seeds are determined primarily by the moisture tension of the soil, but, at the same time, it is affected by the moisture absorbing power of seed, amount of moisture which should be absorbed by the seed for its germination or emergence, and moisture holding capacity or moisture supplying power of soil.

EFFECTS OF GIBBERELLIN TREATMENTS ON GERMINATION OF VARIOUS SPECIES OF WEED SEEDS

Nineteen species of weed seeds collected near Edmonton during 1957 and/or 1958 were tested periodically for their germination percentage with or without treatments with gibberellin. Most of the untreated samples were completely dormant under conditions of the test at harvest time and the majority of the dormant species remained so during a storage period of 6 months at 3 °C. ± 0.5°. Gibberellin treatments of up to 500 p.p.m. in the medium, or of up to 2,000 p.p.m. as a 24-hour pre-soaking treatment, were without appreciable effect on most of the dormant species. The chemical had a significant effect in overcoming dormancy of some, but not all, samples of wild oats. Dormant seeds of wild mustard and stinkweed were very sensitive to gibberellin treatments, while hemp nettle and blue bur showed a smaller response. Differences in results between different lots of certain species emphasize the variable complexity of conditions which at a given time may or may not be responsive to gibberellin in initiating or accelerating the process of germination.

ELECTROCARDIOGRAM OF THE MONTH

Copper (Cu) contamination dramatically affects crop growth and thus threatens crop production; while applications of melatonin (MT) serve as an effective way to tolerate Cu stress for plant development, the underlying mechanism remains largely unknown in rice. Here, we found that Cu toxicity remarkably decreased germination rates and seedling growth compared to the untreated control (CK), while seed priming with a solution of 100 μM MT significantly alleviated the adverse effects on Cu-stressed seeds. In addition, the MT treatment decreased the accumulation of Cu in seedlings at 7 days after imbibition (DAI), possibly through enhanced Cu sequestration, and improved reserve mobilization through the promoted activity of α-amylase and protease in seeds under Cu stress. Interestingly, gibberellin (GA) synthesis was restored to or even exceeded the CK levels in the MT presoaking treatment, while the abscisic acid (ABA) content decreased compared to those of the Cu-stressed seeds, suggesting crosstalk between MT and other phytohormones, e.g., GA and ABA. More importantly, MT pretreatment also significantly promoted the growth of postgermination seedlings. This was largely ascribed to the MT-ameliorated antioxidant system, which consequently reduced the accumulation of Cu stress-induced oxidative products, e.g., hydrogen peroxide (H2O2), malondialdehyde (MDA), and superoxide (O2·_). Collectively, these results demonstrate that seed priming with MT could greatly mitigate the adverse effects of Cu stress on seed germination and subsequent postgermination growth through crosstalk among various defensive response pathways. This study provides vital guidance for applications of MT in agronomic production.

Studies of Soaking Rice Seeds in Water During Cold Seasons Prior to Sowing Time.

1) This experiments has been carried out in order to clarify the various effects of continuous presoaking of rice seed from winter season up to sowing time. 2) The germination and viable seedling percentage decreased in treated plot and the rice seeds which died during the treatment period were found mostly in weak grains. 3) It was found that the seeds sown before 25th April, after the treatment, showed a remarkable increase in grain yield as compared to those sown without treatment. Bnt on the other hand reverse results were obtained, when the seeds were sown later than the above mentioned date. 4) The presoaking treatment might not be the only factor, responsible for the increase of grain yield, bnt the early and thin sowing should also be taken into consideration.

Stubies on the continuous presoaking of rice seed from winter to seeding time : 1. Changes in the seeds buring the presoaking treatment

Absorption of water, loss in nutrient contents and amylase activity of rece seeds during the long-time presoaking treatment were investrgated. The results obtained are as follows : 1) Seeds which are supposed to have strong vitality, as judged from their original location on the mother panicle, are able to absorp water more rapidly than weak grins. 2) The loss of seed contents from the seeds as determined by the decrease of dry-weight during the treatment differs with the different groups of seeds obtained form the different locations on panicle. Sudden inerease of dry-weight loss was observed during April, due apparently to higher temperature. 3) High amylase aetivity was observed in the treated sample of seeds as compared with the control.