Viscosity Of Juice Research Articles

Effect of Dietary Fiber on Pancreatic Enzyme Activity In Vitro

The importance of various factors for dietary fiber effects on pancreatic enzyme activities was studied in vitro. Pectin of high methylic esterification and guar gum, which reduced enzyme activities, particularly lipase activity, increased the viscosity of duodenal juice. Increasing duodenal juice viscosity by polyethlene glycol also caused a reduction particularly of lipase activity. Pectin of low methylic esterification, which reduced especially amylase and lipase activities, significantly lowered duodenal juice pH. Lowering duodenal juice pH by hydrochloric acid caused a reduction especially of amylase and lipase activities. Pretreating fiber at acid pH tended to increase its enzyme-inhibiting properties. Trypsin adsorption to wheat bran was partly reversible by buffer washings. Changing ionic strength and incubation time appeared relatively unimportant for the effects of the fiber on enzymes. It is assumed that the inhibitory effects of the fiber on enzymes are attributed inter alia to effects on viscosity, pH, and adsorption, and further that gastric acidification of fiber and conditions lowering intestinal pH may enhance these effects.

Structural Collapse and Volatile Retention During Heating and Rehumidification of Freeze‐Dried Tomato Juice

ABSTRACTThe effects of temperature, moisture content, and pectin addition on the “collapse” of freeze‐dried tomato juice cake and retention of volatiles were investigated. High temperatures and high moisture contents induce collapse and the loss of volatiles, which was measured with 14C‐labelled butyl acetate. The addition of pectin, which enhances the viscosity of the tomato juice, increases its “collapse” temperature after freeze‐drying and the retention of volatiles.

Rheological Properties of Prune Juice

ABSTRACTThe effect of preparation procedures, raw material and additives on prune juice viscosity was investigated. Prune juice preparation procedure had the greatest effect on juice viscosity of any parameters studied, with the disintegration process producing juice having higher viscosity than the diffusion process. Juice viscosity decreased during elevated storage temperatures. Also, prune size and maturity influenced viscosity, with smaller prunes harvested early in the season producing juice with higher viscosities. In diffusion juice extraction, the first leach product had a lower viscosity, lighter color and higher potassium content that the rest. Prune concentrate over 45° brix exhibited dilatant properties.

Viscosity and electrolyte concentrations in gastric juice from cystic fibrosis children compared to healthy children.

The viscosity of gastric juice and the concentrations of sodium, potassium, calcium, magnesium and chloride ions were measured before and after stimulation with pentagastrin in 10 children with cystic fibrosis and compared to those in 10 healthy children of corresponding ages. The viscosity values followed the same patterns as those for the sodium and calcium ion concentrations and were higher in the cystic fibrosis group. The electrolyte concentrations in the basal and different post-stimulation fractions of the gastric juice were higher in the cystic fibrosis group. Significant differences between both groups could only be found in the electrolyte concentrations. The total secretion of each of the electrolytes was the same in both groups because along with the increased electrolyte concentration in the cystic fibrosis group there was a reduced volume of gastric juice. The dependence of viscosity on the individual electrolyte concentration is discussed. The differences in the viscosity and the electrolyte concentrations in gastric juice from the cystic fibrosis children seems to be due to changes in the process of gastric secretion and not due to the influence of swallowed saliva.

CHARACTERISTICS OF JUICE, PUREE AND WHOLE TOMATOES PROCESSED FROM NOR HYBRID FRUITS

ABSTRACTChemical and physical properties of processed tomato products from Heinz(H) 1439 and H1439 ×nor fruits were examined. Levels of total solids and viscosity were enhanced while pH was reduced in juice and puree made from nor hybrid fruits. Increased levels of pectic substances, especially those solubilized by sodium hexametaphosphate, contributed to the elevated total solids content and viscosity of juice and puree. Levels of citric acid were similar in juice from both genotypes. Malic acid content in juice from nor hybrid fruits was more than twice that contained in its homozygous counterpart. While red color was less in nor hybrid whole canned tomatoes as indicated from CDM values, sensory evaluations for color were nonsignificant. Tomatidine levels were reduced in juice from nor hybrid fruits while no differences in phenolic levels were detected between the two genotypes. Weight loss was reduced and shear values enhanced in whole canned tomatoes of the nor hybrid genotype which might be attributed to enhanced levels of pectic substances. Utilization of nor hybrid fruits for processed tomato products appears to provide certain improvements in quality, especially total solids and viscosity, without detrimentally influencing other attributes.

カンキツの果汁に関する基礎的研究

This study was conducted for two seasons in 1974 and 1975 during Satuma mandarin (Citrus unshiu MARC.) development to determine changes in the viscosity of the fruit juice, the relation between such changes and the morphological and the histological changes and the correlation between those variables for the fruit sampling dates.(1) A certain pattern in the changes in viscosity of fruit juice was recognized during fruit development. This pattern was divided into three stages. Stage-1 was period of rapid increase in viscosity from early July to early August. This period corresponded with the first half of enlargment of fruit cells. Stage-2 was characterized by a period of considerable decrease in the viscosity of the fruit juice. This period agreed closely with the latter part of enlargment of cell in the fruit from early in August to the second part of September with Wase unshiu or to the second part of October with Futsu unshiu. The viscosity of the fruit juice was increased again slowly in stage-3 by the accumlation of sugar and the other materials. This period was regarded as the maturation period.(2) The viscosity of fruit juice of Futsu unshiu was higher than Wase unshiu through the whole period. The viscosity of fruit juice with Wase unshiu and Futsu unshiu in the 1974 season was higher value than for the 1975 season. The difference in viscosity of fruit juice seemed to correspond with changes in meterological and the other enviromental conditions.(3) In this experiment, the higher the viscosity of juice in the sampled fruit at the first date, the more its value was on the second date. Therefore, the correlation between the viscosity of juice in the sampled fruit on each date was analyzed. There was a high positive correlation between the viscosity of juice in the sampled fruit at the preceeding time and the latter time, for example the first time and the second time, the second time and the third time. The correlation coefficient of Wase unshiu and Futsu unshiu was above 0.8 through the whole period. The juice viscosity for sampled fruit at the end date of stages 1, 2 and 3 was positively correlated with the viscosity of juice in the sampled fruit on the respective preceeding date for a time internal in each stage and the greater the sampling period from the preceeding date to the end date was a shorter period of days, the higher their correlation coefficient was. Their correlation coefficent was significant at the 1% level.From the experimental results described above, the changes in viscosity of fruit juice during fruit development was considered to be a useful index for determing fruit taste taste and producing sweet fruit.

Inheritance and Evaluation of Alcohol Insoluble Solids of Tomatoes as a Secondary Character in Selection for Juice Viscosity1

Abstract Segregation for alcohol insoluble solids (AIS) in F2 and first backcross generations from a cross with ‘VF109’ and ‘Campbell 146’ as high and low parents, indicated 2 gene-pairs controlling AIS. Broad-sense heritability estimate for AIS was 84%, of which 62% was due to additive and 22% due to non-additive gene action. AIS had high phenotypic correlation with viscosity. The genotypic correlation was also high (rG = 0.89). The relative selection efficiency (RSE) of indirect selection, using AIS as a secondary character, was estimated to be 114% of the direct selection. Thus AIS may be useful as a secondary character for indirect selection of increased juice viscosity of tomatoes.

Juice viscosity as related to various juice constituents and fruit characters in tomatoes

Alcohol insoluble solid content (AIS) of tomato fruits was found to be highly correlated with viscosity. The correlation coefficient values, based on 12 cultivars, were r=0.97 for AIS of whole fruit extracted with 50% ethanol and r=0.94, extraction with 75% ethanol. The correlation of AIS with viscosity was high for outer pericarp, r=0.93, and inner pericarp, r=0.78, but low for locular contents, r=0.18. A principal component analysis indicated that fruit size, shape and firmness, total solids, proportion of outer and inner pericarp, and locular contents were not highly associated with either AIS or viscosity. Their consequences for a breeding program are discussed.

PASSION FRUIT STARCH AND EFFECT ON JUICE VISCOSITY

Starches in the juices of yellow passion fruit, Passiflora edulis f. flavicarpa, and purple passion fruit, P. edulis f. edulis, were isolated and characterized. Starch granule sizes for the yellow variety (7.8 μm) and purple variety (6.4 μm) were similar. Gelation temperature ranges for the yellow variety (58.5–67.0 ° c) and purple variety (58.5–66.5 ° C) were also similar. The amylose content was slightly higher in the yellow variety (8.7%) than in the purple variety (5.8%). Viscosity differences between juices of the two varieties after treatment with heat and α‐amylase were attributed to differences in pH and starch content between the yellow variety (pH 2.8, 0.06% starch) and the purple variety (pH 4.2, 0.74% starch). α‐amylase was effective in reducing the viscosity of passion fruit juice in which the starches are gelatinized.

The Effect of Chlorflurenol on Set and Concentrated Yield of Processing Tomatoes1

Abstract A single spraying of 2-chloro-9-hydroxyfluorene-9-carboxylic acid (chlorflurenol) on the foliage increased the set rate of processing tomatoes under conditions of high temperature as compared with untreated control or 4-CPA-treated plants. As the rate applied increased, chlorflurenol inhibited vegetative growth, increased fruit malformation, and decreased the pH of fruit juice (0.1 unit). No differences could be detected in juice viscosity and in total soluble solids of treated and control fruits.

Sampling variation in alcohol insoluble solid content and viscosity of tomato juice

SummaryThe influence of various factors on the alcohol insoluble solids content (AIS) and viscosity of tomato juice was studied. The results showed that different levels of fruit ripeness affected AIS but exposure of the fruit to sun or shade had no effect. A late planted crop had a higher AIS than one planted earlier. Pickings within a season differed significantly in both ATS and viscosity but the cultivar χ picking interaction was not significant.

VISCOSITY AS AFFECTED BY VARIOUS CONSTITUENTS OF TOMATO JUICE

SUMMARY— Degradation of proteins of tomato juice with pronase caused a relatively small loss of viscosity. Commercial cellulase freed of pectolytic activity with 8 M urea greatly decreased the viscosity of washed tomato solids. Further degradation with pectinase was ineffective in reducing viscosity. Cellulase extracted from the tomato lowered viscosity of tomato juice. Enzymatic degradation as indicated by chemical analysis did not always result in a loss of viscosity. By extracting the solids with water, viscosity of tomato juice was lowered drastically. The extent of the reduction was not affected by previous treatment with cellulase or pectinase. Viscosity was not affected by extraction with versene. The greater reduction in viscosity of tomato juice by extraction of the solids with water than with ethanol indicates that the high molecular polymers associated with the insoluble solids contribute greatly to viscosity. The data did not indicate a significant contribution of the uronides to the viscosity of tomato juice.

EFFECT OF TEMPERATURE ON VISCOSITY OF FRUIT JUICES AND PUREES

SUMMARY: The viscosities of selected fruit juices and purees were measured with a coaxial‐cylinder viscometer in the temperature range 20–70°C. Depectinized apple juice and Concord grape juice were Newtonian fluids at all concentrations and their viscosity decreased considerably at higher temperatures. Cloudy apple and orange juices changed from Newtonian to pseudoplastic at concentrations higher than 50 and 20° Brix. respectively. Temperature had a smaller effect on viscosity of cloudy juices than of clear juices. The apparent viscosity of fruit purees (pseudoplastic fluids) decreased slightly at higher temperatures. The activation energy for flow increased with the juice concentration and decreased with the presence of suspended particles in the fruit product. The data and conclusions are useful in the design and operation of efficient food‐processing equipment.

Irradiation du Jus de Pomme I. Effets des rayons γ sur Ie taux de filtration et Ia viscosité

Freshly extracted, apple juice was submitted to different doses of γ rays (75 to 600 Krads). Filtration rates were measured and it was observed that, by increasing the dose of irradiation, the filtration rate was increased. A minimum of 150 Krads appeared necessary to produce changes in filtration ability. Observations on the viscosity of irradiated juices are in the same order as those made on the filtration rates: as the dose increases, the viscosity decreases. However differences in viscosity do not explain alone differences in filtration rates. It has been observed that a gel is formed on the surface of the filter and irradiation decreases this formation.

A Modified Sample Holder for Determining Viscosity of a Diphasic Fluid

SUMMARY— A sample holder was constructed to prevent separation in a diphasic fluid during the determination of viscosity with a disc‐spindle viscometer. The holder consists of inner and outer cups separated with spacers. A magnetic stirrer causes fluid being tested to move through holes in the bottom, up around the outside, and over the top of the inner cup, creating a slow downward movement past the spindle. The movement is adjusted to a rate just sufficient to maintain a homogenous mixture and give a maximum stabilized shearing stress.Shearing stress was unaffected by direction of rotation of the stirrer. The agitation required for tomato juice apparently had but little effect upon shearing stress as indicated by tests with Newtonian fluids.The modified sample holder was used to determine viscosity of juices of several varieties varying in fruit characteristics. large differences were shown, but no relationship between fruit firmness and viscosity was apparent.

Increase in Viscosity and Gel Formation of Fruit Juice by Purified Pectinesterase

The pectinesterase produced by Sclerotinia libertiana was purified by the column chromatography employing cation exchange resin Amberlite CG 50 and CM cellulose. The specific activity per mg protein was increased 266-fold. The homogeneity of the enzyme preparation was confirmed by ultracentrifugal analysis and starch zone electrophoresis. The purified pectinestrase was found to remarkably increase the viscosity of pectin solution and fruit juice, and, in a pectin solution of appropriate concentration (about 0.5~1 %) and some fruit juices, it finally formed the cosity thus increased and gel formed by the enzyme action did not change for a long time.

STUDIES ON TABLET DISINTEGRATION. I. THE EFFECT OF PENETRATING RATE ON TABLET DISINTEGRATION.

The effects of the penetrating rate on tablet disintegration were examined. Viscosity, surface tension, contact angle of liquid and the mean capillary diameter of tablet were measured and their effects on disintegration were discussed. In high viscosity solution, the rate of penetration decreased and the disintegration was not well. The viscosity of gastric juice was measured and tablet disintegration in human gastro-intestinal tract was examined by X ray. It was estimated that a tablet disintegration might be affected by the viscosity of gastric juice. The rate of penetration of powder in a surfactant solutions and the penetration of the powder coated by surfactant in pure water were measured. The effect of surfactant on disintegration could not be generally expected due to the decrease of surface tension. The mean diameter of open capillary in a tablet was measured by air permeametry. The diameter was decreased by a large compressional force in tableting and increased by a large quantity of disintegrator. The equation of penetrating rate was discussed theoretically to apply it for the penetrating in tablet capillary. It was concluded that Washburn's equation of penetrating rate could be applied to the penetrating in the capillary of a tablet.

Possible applications of ionizing radiations in the fruit, vegetable and related industries

Some effects of γ-radiation have been observed on the texture, flavour and processing properties of fruits and vegetables. An appreciable reduction in mould decay of strawberries during storage at 20°C and 1°C has been observed after treatment with 0·2 to 0·4 Mrad. Flavour was affected slightly and the viscosity of the juice was reduced considerably. The viscosity of juice extracted from irradiated whole berries, was reduced considerably by doses between 0·4 and 0·6 Mrad without critically affecting the flavour of the juice. The irradiated berries were free from a significant number of mould spores. No immediate commercial application was foreseen in the blackcurrant juice industry. Plums were shown to be free from mould after a treatment of 0·4 Mrad and the initial spore count of apples is considerably reduced by a dose of 0·2 Mrad. Some evidence has been obtained that the softening of pears can be delayed by a dose of 0·3 and 0·5 Mrad. The published literature on the effects of radiation on other fruits and vegetables has been reviewed and commented upon.

Effect of Cigarette Smoking on Dissolved Gastric Mucins and Viscosity of Gastric Juice

Effect of Cigarette Smoking on Dissolved Gastric Mucins and Viscosity of Gastric Juice

Sugar-cane juice clarification for syrup manufacture

A continuous clarification of grape juice was undertaken in a packed bed reactor (PBR) using pectinase enzymes immobilized on glass beads. The enzyme immobilization process decreased the specific activity and the volumetric productivity from 3 ± 0.2 to 2.7 ± 0.1 units mg−1 and from ~0.085 to ~0.070 mg mL−1 min−1, respectively. Also, it increased the optimum pH from 5.0 to 5.5, but did not influence the optimum temperature (50 °C). The best conditions for clarification of the grape juice were obtained at a flow rate of 0.5 mL min−1 and a treatment time of 42 min. After clarification, pH, total soluble solids, turbidity, total phenolic content, antiradical activity and viscosity of grape juice were decreased, and on the other hand, total titratable acidity and the color parameter L were increased. Generally, this study showed that the continuous operation in a PBR including glass bead immobilized enzyme can be a potential alternative for the batch system used in juice industries.