Showing papers in "Journal of Food Science in 1980"
TL;DR: Differential scanning calcorimetry (DSC) was used to study gelatinization phenomena of corn, potato, acid-modified corn and smooth pea, and various legume starches.
Abstract: Differential Scanning Calorimetry (DSC) was used to study gelatinization phenomena of corn, potato, acid-modified corn and smooth pea, and various legume starches. Two endothermic transitions were observed for starches heated in the presence of limited amounts of water (starch/water = 46–48% w/w). The effect of starch concentration on the shape of these two endotherms was studied for three legume starches. Considering the starch granule as a spherulite, the experimental data were treated thermodynamically by applying equations describing phase transitions of semi-crystalline polymers. Experimental evidence suggested that a solvation-assisted melting of starch crystallites took place during gelatinization and that the process was facilitated by the presence of the amorphous parts of the granule. The enthalpy change, ΔH, associated with the gelatinization varied among these starches within a range of 2.6–4.4 Cal/g. A comparison between DSC transition temperatures and characteristic gelatinization temperatures obtained by other methods was also made.
488 citations
TL;DR: In this article, the effect of food color and flavor levels on the perceived flavor intensity and hedonic quality of non-carbonated beverages and cake was investigated. But the results showed that the overall acceptability of both the beverage and cake products was more closely associated with ratings of flavor acceptability than with color acceptability, while a test of colorant safety information did not decrease any aspect of a product's acceptability.
Abstract: Four experiments were conducted to assess the effect of food color on flavor identification of noncarbonated beverages and to assess the interactive effect of food color and flavor levels on the perceived flavor intensity and hedonic quality of beverages and cake. Results showed that color masking dramatically decreased flavor identification of fruit-flavored beverages, while atypical colors induced incorrect flavor responses that were characteristically associated with the atypical color. In addition, the color level of beverages had significant effects on their overall acceptability, acceptability of color and of flavor, as well as on flavor intensity. The same results were shown with cake samples, with the exception that a significant interaction of color and flavor level was observed on overall acceptability. Correlational analysis on the subjective dimensions showed that the overall acceptability of both the beverage and cake products was more closely associated with ratings of flavor acceptability than with ratings of color acceptability. In addition, a test of the effect of colorant safety information showed that such information did not decrease any aspect of a product's acceptability.
282 citations
TL;DR: In this paper, three forms of pectinesterase, accounting for 95% of the activity in Navel orange, showed considerable differences in heat stability and orange juice cloud destabilizing properties.
Abstract: Three forms of pectinesterase, accounting for 95% of the activity in Navel orange, showed considerable differences in heat stability and orange juice cloud destabilizing properties. Pectinesterase I and II (isoenzymes) and a so-called high molecular weight pectinesterase were rapidly inactivated at 70°C, 60°C, and 90°C, respectively. In chilled juices (5°C) the high molecular weight pectinesterise was the only enzyme which rapidly produced methanol and destabilized the cloud. Although this enzyme represents only 5% of the total pectinesterase activity in Navel orange, it is thought that it is largely responsible for gelation which may occur in concentrates produced by the cut-back process.
271 citations
TL;DR: At spice concentrations to 2% in growth media, gram positive bacteria were more sensitive than gram negative bacteria, and sage had the highest antibacterial activity, followed closely by rosemary, which enhanced the antibacterial effect.
Abstract: The sensitivity of 22 gram negative and 24 gram positive bacteria to the spices sage, rosemary, and allspice was studied. At spice concentrations to 2% in growth media, gram positive bacteria were more sensitive than gram negative bacteria, and sage had the highest antibacterial activity, followed closely by rosemary. A concentration of 0.3% of either sage or rosemary in the media inhibited growth of 21 gram positive organisms, 9 of which were enteropathogenic. Two Kanagawa positive strains of Vibrio parahaemolyticus were also inhibited. Allspice was the least effective, requiring more than 0.5% for growth inhibition of most of the tested strains. Recovery of growth was observed after inhibition at 0.3% concentration of sage or rosemary, whereas a concentration of 0.5% was bactericidal. A combination of sage and rosemary enhanced the antibacterial effect.
201 citations
TL;DR: In this paper, a simple procedure has been implemented to measure porosity of apples as a function of moisture contents, and it is shown that the pores which for biological reasons are open, i.e. connected to the outside, remain so until X = 1.5 g/g.
Abstract: A simple procedure has been implemented to measure porosity of apples as a function of moisture contents. The method has been applied to apples with change in moisture contents by conventional air drying. It is shown that the pores, which for biological reasons are open, i.e. connected to the outside, at the onset of dehydration, remain so until X = 1.5 g/g. As dehydration proceeds the pores are split into two families of pores: externally connected pores and locked-in bores. Both total and open pore porosity can be predicted from experimental correlations. Alternatively, the total porosity can be estimated from data on bulk volume shrinkage and the average composition of the tissue by means of equations presented. The interpretation of experimental data using this approach confirms that there is a significant change in the three-dimensional arrangement of the cellular tissue below X = 1.5 g/g. The two approaches lead to the conclusion that, probably due to cellular collapse, the open structure that characterizes the fresh foodstuff changes into a structure with locked-in pores. This fact may help to explain the slow and difficult re-hydration which characterizes air-dried foodstuffs. This hypothesis will be followed up in future work. The information developed should be of help in qualitative and quantitative modeling of processes involving moisture changes.
197 citations
TL;DR: In this paper, the rate and degree of extraction of anthocyanins from grape pomace depends upon a number of factors; this research concerned two: solvent (ethanol, methanol, water), and acid (HCl, citric, tartaric, formic, acetic, propionic).
Abstract: There is considerable interest in utilization of natural pigment as food colorants, particularly from raw materials in adequate supply, such as wine grape pomace. The rate and degree of extraction of anthocyanins from grape pomace depends upon a number of factors; this research concerned two: solvent (ethanol, methanol, water), and acid (HCl, citric, tartaric, formic, acetic, propionic). Methanol was the best extractant being 20% more effective than ethanol and 73% more effective than water. HCl was most effective with ethanol, but is also very corrosive. Of the organic acids, citric was most effective with methanol and acetic acid with water.
190 citations
TL;DR: The results indicate that an extension of the shelf-life of fresh fish can be obtained by packaging and storing the fish in a CO2 atmosphere.
Abstract: Modified atmosphere packaging using CO, was demonstrated to be effective in retarding the growth of microorganisms during storage of fresh fish from the Gulf of Mexico. At 4°C, there was at least a log difference in bacterial counts at 2, 4, and 6 days between fish stored in CO2 as compared to control fish stored without CO2. While the CO2 atmosphere was shown to inhibit the growth of common spoilage types of bacteria such as gram-negative rods (Pseudomonas), stimulation of gram-positive bacteria such asLacto-bacillus was also demonstrated. Fish stored at 4°C for 2–8 days in a modified atmosphere containing CO2 had lower TVN values than fish stored at the same temperature without CO2. The results indicate that an extension of the shelf-life of fresh fish can be obtained by packaging and storing the fish in a CO2 atmosphere.
174 citations
TL;DR: A mathematical model describing simultaneous water diffusion and gelatinization of starch during rice parboiling is proposed in this paper, which shows good correlation between observed and predicted value of water uptake.
Abstract: A mathematical model describing simultaneous water diffusion and gelatinization of starch during rice parboiling is proposed. Soaking experiments were conducted on a short-grain rice variety. A computer-aided nonlinear optimization technique is used to find diffusion coefficients and reaction rate constants in the temperature range 50-120°C. It is concluded that the parboiling process is limited by the reaction of starch with water below 85° C and by diffusion of water above 85° C. The activation energy was found to be about half in case of diffusion limited process than that of reaction limited process. The study showed that it is possible to reduce energy input if rice is dehusked before parboiling. The mathematical model shows good correlation between observed and predicted value of water uptake.
167 citations
TL;DR: In this article, the effects of frozen storage on meat components were evaluated to evaluate effects on frankfurter quality, and the results showed that frozen storage significantly affected beef and pork lean (drip loss, % solids and N in drip, extractable protein, water binding, emulsifying capacity).
Abstract: Frankfurter quality was monitored to evaluate effects of frozen storage on meat components. After fresh meat controls were tested, beef, pork, and pork fat were frozen and stored at −17.8°C for 1–37 wk. At 6-wk intervals, functional and quality tests were performed on thawed and control meat samples and on frankfurters made from the samples. Frozen storage significantly affected beef and pork lean (drip loss, % solids and N in drip, extractable protein, water binding, emulsifying capacity) and fat (beef-thiobarbituric acid and pork-peroxide values); frankfurters produced from these ingredients were also affected (cooking tests, penetration force, sensory panel scores).
153 citations
TL;DR: In this paper, ground beef patties were prepared from varying fat sources to final raw fat contents of 16, 20, 24, and 28%, and trained sensory panelists evaluated each treatment for differences in tenderness, juiciness, connective tissue amount, mouth coating effect, and ground beef flavor intensity.
Abstract: Ground beef patties were prepared from varying fat sources to final raw fat contents of 16, 20, 24, and 28%. Trained sensory panelists evaluated each treatment for differences in tenderness, juiciness, connective tissue amount, mouth coating effect, and ground beef flavor intensity. Other patty characteristics examined included raw and cooked fat and moisture, cooking losses, Instron shear force, and total and percentage of soluble collagen. Generally, increasing fat levels in formulations resulted in higher tenderness and juiciness scores and ratings indicative of lower connective tissue amount. Neither collagen content nor total cooking loss was significantly affected by fat level. Sensory ratings and cooking properties were not significantly affected by fat source.
151 citations
TL;DR: The results suggest that naturally occurring hydroxycinnamates may interfere with the fermentation of fruits by this yeast.
Abstract: The antifungal activities of caffeic, p-coumaric, ferulic, and chloro-genie acids against Saccharomyces cerevisiae were investigated. Caffeic acid was found to exhibit little inhibition of growth, although the lag period was extended in the presence of 1000 ppm. Chloro-genie acid had no effect on the organism. In contrast, p-coumaric acid at 100 ppm increased the lag phase of S. cerevisiae, and above 250 ppm, inhibition after 72 hr growth was proportional to the concentration present. Ferulic acid caused an increase in lag phase at 50 ppm, while as little as 250 ppm resulted in complete inhibition. These results suggest that naturally occurring hydroxycinnamates may interfere with the fermentation of fruits by this yeast.
TL;DR: In this article, nine combinations of sodium chloride (NaCl), potassium chloride (KCI), and magnesium chloride (MgCl2) at high and low ionic strengths (IS) (042 and 021 respectively) and low IS with 013% tripotassium phosphate (K3PO4) were used to determine the effects of a reduction or partial replacement of sodium on bologna characteristics and acceptability.
Abstract: Nine combinations of sodium chloride (NaCl), potassium chloride (KCI), and magnesium chloride (MgCl2,) at high and low ionic strengths (IS) (042 and 021 respectively) and low IS with 013% tripotassium phosphate (K3PO4) were used to determine the effects of a reduction or partial replacement of sodium on bologna characteristics and acceptability The NaCl-MgCl2 had significantly (P < 005) less stable and firm emulsion and compression hardness than NaCl or NaCl-KCl treatments Low IS treatments had significantly less stable and firm emulsions and lower compression hardness than high IS treatments Adding PO4 to low IS treatments produced products similar to high IS treatments Only slight textural changes occurred in products after 14 days of cooler (1°C) storage High IS NaCl and NaCl-KCl and low IS NaCl-PO4, NaCl-MgCl2 -PO4 and NaCl-KCl-PO4 were found acceptable for flavor, texture, and color by consumer panels
TL;DR: In this article, the authors investigated the emulsifying properties of the 7s protein rich fraction (7s PRF) and the 1 IS PRF using refined soybean oil.
Abstract: The emulsifying properties of the 7s protein rich fraction (7s PRF) and the 1 IS protein rich fraction (11s PRF) were investigated using refined soybean oil. The emulsifying capacity and emulsion stability of the 7s PRF generally showed higher values than those of the 11s PRF in the pH range 2–10. The same phenomenon was observed with the 7s PRF and 11s PRF partially hydrolyzed by dilute HCl. The emulsifying properties of the acid-precipitated protein (APP) and the 7s PRF showed the lowest value at around pH 4.5, and were closely related to the behavior of protein solubility. The emulsion stability of the 11s PRF, however, showed its lowest value at around pH 7 and did not necessarily correlate with its solubility. The breaking stress of the emulsions introduced from both the 7s PRF and the 1 1s PRF increased in accordance with oil phase volume. While the breaking stress of the 7s PRF-introduced emulsions were little affected by heat treatment of the protein solution, considerable effect was observed with the 1 1s PRF-introduced emulsions. The breaking stress of the 1 1s PRF-introduced emulsions increased markedly as the protein concentration increased. The heat treatment of the protein solution at 95° C for 5 min prior to emulsification increased the breaking stress to two to four times higher than that of emulsions without the heat treatment.
TL;DR: Six lamb carcasses were split, the left side was electrically stimulated and a significant decrease in specific sedimentable activity and total activity of both enzymes was found for the ES samples, indicating that the lysosomal membranes are disrupted due to electrical stimulation.
Abstract: Six lamb carcasses were split, the left side (ES) was electrically stimulated (25 pulses, 0.5–1 set each at 440V) while the right side (C) served as an unstimulated control. Samples were removed at 1 hr post-stimulation and assayed for total, free, and specific activities of the lysosomal enzymes β-glucuronidase and cathepsin-C. A significant (P < 0.05) increase in percent free activity and a significant decrease in specific sedimentable activity and total activity of both enzymes was found for the ES samples. This indicates that the lysosomal membranes are disrupted due to electrical stimulation. The possible effects of the free lysosomal enzymes on muscle proteins and meat tenderness is discussed.
TL;DR: In this article, the effects of relative humidity during storage on the physicochemical state of lactose, a major constituent of spray-dried whey powders, were evaluated by means of moisture sorption isotherms and the Scanning Electron Microscope (SEM).
Abstract: The objective of the present study was to evaluate, by means of moisture sorption isotherms and the Scanning Electron Microscope (SEM), the effects of relative humidity during storage on the physicochemical state of lactose, a major constituent of spray-dried whey powders. Lactose, which is present in whey powders at about 70%/weight levels, can be in either the amorphous or crystalline form depending upon processing conditions during the drying treatment. Two spray-dried whey powders were examined: a hygroscopic spray-dried sweet whey powder (HW) in which the lactose was chiefly in the amorphous form, and a nonhygroscopic spray-dried sweet whey powder (NHW) which contained a mixture of both amorphous and crystalline lactose. Moisture adsorption isotherms at 25°C under vacuum over saturated salt solutions in the water activity (a,) range 0.1l-0.85 were determined by weighing periodically over a 6-wk period. The adsorption isotherm for the nonhygroscopic whey (NHW) samples was continuous or smooth over the entire a, range; however, the adsorption isotherm for the hygroscopic whey (HW) samples had a break in the 0.33-0.44 aw range. Work with the Scanning Electron Microscope (SEM) indicated that in HW samples, lactose crystals were present at an aw of 0.33 and above. Examination of the NHW samples with the SEM indicated the presence of lactose crystals at all aw levels up to 0.75. In both the HW and NHW powders, the amount of lactose crystallization appeared to increase with increasing aw above 0.40, indicating a continuing shift from amorphous to crystalline lactose. This was also confirmed for both whey powders since they both lost weight after an initial rapid gain during the 6-wk period at an aw of 0.40 and above followed by another weight gain at the higher aw’s.
TL;DR: In this paper, the effects of variables on the properties of the emulsion prepared from a whey protein dispersion and coconut oil were studied, and the importance of electrostatic nature and conformation of the proteins in the adsorption was suggested.
Abstract: The effects of variables on the properties of the emulsion prepared from a whey protein dispersion and coconut oil were studied. Adsorption of the protein on to the fat globule surface was also investigated. A stable emulsion was obtained at the protein concentrations more than 2%. The creaming stability was minimal and the viscosity was maximum at pH 5 over the range of pH 3-9. Addition of sugar ester, monostearate, and lecithin rather depressed the creaming stability. The emulsion was heat stable in the absence of salt, but became a gel on heating in the presence of CaCl2, The fat globule size and the amount of protein adsorbed on to the fat globule surface were highest at pH 5. SDS-electrophoresis of the protein recovered from the surface revealed that β-lactoglobulin, immunoglobulin, and lactoferrin were selectively adsorbed at pH 7. The adsorption of α-lactalbumin markedly increased and that of β-lactoglobulin decreased with the decrease in pH to 5 or 3. The importance of electrostatic nature and conformation of the proteins in the adsorption was suggested.
TL;DR: The effects of germination, cooking and canning on the changes in total phosphorus, inorganic phosphorus and phytate retention in black-eyed, red kidney, mung, and pink beans were determined in this article.
Abstract: The effects of germination, cooking and canning on the changes in total phosphorus, inorganic phosphorus and phytate retention in black-eyed, red kidney, mung, and pink beans were determined in this study. Soaking the dry beans in water for 12 hr at 24°C resulted in a slight decrease in phytate. After germination for 96 hr or longer there was a significant breakdown in phytic acid, and an increase in inorganic phosphorus. Cooking the dry beans at 100°C for 3 hr had little effect on phytate retention. Heat processing the dry beans at 1155°C for 3 hr in cans resulted in some increase in inorganic phosphorus and a reduction in phytate.
TL;DR: The levels of sorbitol, mannitol, xylitol, and xylose in several Finnish wild berries were determined gas chromatographically as discussed by the authors, and the highest amount of xylols occurred in raspberries (Rubus idueus) (approx 400 μg per 1.0g of fresh weight).
Abstract: The levels of sorbitol, mannitol, xylitol, and xylose in several Finnish wild berries were determined gas chromatographically. The highest amount of xylitol occurred in raspberries (Rubus idueus) (approx 400 μg per 1.0g of fresh weight). In other fruits the concentrations ranged from 7.5–280 pg per 1.0g of fresh weight. Sorbitol and mannitol occurred most abundantly in Iowan berries (Sorbus aucuparia) (up to 5.3 and 0.38 mg per 1.0g of fresh weight, respectively). The highest amount of xylose was detected in ripe cranberries (Vuccinum oxycoccus) (320 pg per 1.0g of fresh weight). There was no consistent correlation between ripeness and the levels of sugar alcohols, except for sorbitol, the levels of which increased during the ripening of rowan berries.
TL;DR: In this paper, the densities of food products undergoing baking processes in commercial multi-zone band ovens of a local plant were measured with a volume replacement method along with a photographic procedure.
Abstract: The densities of food products undergoing baking processes in commercial multi-zone band ovens of a local plant were measured with a volume replacement method along with a photographic procedure. Three kinds of cookies were selected as the sample products. It was found that the densities are closely related to the temperature and moisture content of cookies during the baking processes. This relationship is statistically represented by polynomial regression equations. The correlation coefficients were better than 0.970. According to the examination of changes in volume of cookies undergoing baking processes, expansion ratios were found to be 2.0-2.5.
TL;DR: In this paper, dry yellow peas, lentils, and faba beans were germinated under laboratory conditions, and a marked increase in ascorbic acid of the legumes was observed during germination.
Abstract: Dry yellow peas, lentils, and faba beans were germinated under laboratory conditions. Periodic rinsing with water at 2-hr intervals was effective in controlling microbial growth. Marked increase in ascorbic acid of the legumes was observed during germination. Amino acid contents did not change appreciably after 4day germination. Wheat flour blends containing ungerminated and germinated legume flours at 5, 10, and 15% levels were used in baking studies. Addition of 15% legume flours to bread resulted in only small deleterious effects on loaf volume, crumb grain, and flavor. Germination adversely affected the baking properties of peas and lentils, but not faba beans. Blanching of the germinated peas further impaired its baking properties.
TL;DR: The heat-induced gelling of ovalbumin solutions (8.2%) has been studied as a function of pH and ionic strength and the results suggest that ovalbumIn gelling is governed primarily by electrostatic forces.
Abstract: The heat-induced gelling of ovalbumin solutions (8.2%) has been studied as a function of pH and ionic strength. At low ionic strengths, plots of gel rigidity against pH passed through a maximum on each side of the isoelectric point (PI). The maximum on the acid side had a higher absolute value and occurred at a higher net charge on the protein than the one on the alkaline side. Increasing the ionic strength shifted the two maxima away from the PI. The results suggest that ovalbumin gelling is governed primarily by electrostatic forces.
TL;DR: In this paper, fish fillets and salmon steaks were held in atmospheres containing 20% or 40% carbon dioxide, with or without 1% carbon monoxide, at intervals of refrigerated storage up to 14 days, for sensory, chemical, and microbiological analyses.
Abstract: Rockfish (Sebastes miniatus) fillets and salmon (Oncorhynchus kisutch) steaks were held in atmospheres containing 20% or 40% carbon dioxide, with or without 1% carbon monoxide. Controls were stored similarly in air. At intervals of refrigerated storage up to 14 days, samples were removed for sensory, chemical, and microbiological analyses. At 7 days, all treatment groups were significantly different visually, with appearance of slime on the air controls, but not on samples in the gas treatments. Samples held in air were judged by panelists to have stronger aromas than others held under carbon dioxide at either level. The higher level of carbon dioxide was more effective. Values for thiobarbituric acid were low in all groups; hypoxanthine values varied widely, with no particular effect due to modified atmospheres. Storage under carbon dioxide was effective in reducing the formation of trimethylamine and ammonia, and markedly inhibited microbial growth.
TL;DR: In this article, two varieties of peanuts, Runner #1 and Spanish, were roasted at 163°C for 7, 8, and 9 min to produce light, medium, and dark roast samples.
Abstract: Two varieties of peanuts, Runner #1 and Spanish, were roasted at 163°C for 7, 8, and 9 min to produce light, medium, and dark roast samples. Sensory evaluation was conducted with a trained panel using a 9-point hedonic scale to rate strength and desirability of odor and flavor. An analysis of variance performed on panel scores produced a standard deviation of 1.81. Statistically significant differences were found among varieties and roasting conditions. Volatile components were collected on Tenax GC followed by characterization and quantitation by gas chromatography (CC). Statistical analysis was used to correlate sensory and instrumental analysis. Stepwise regression showed good correlation between sensory properties and selected GC peaks. The coefficient of determination for the selected peaks averaged 0.9580. Prediction of strength and flavor quality will be possible using the developed equation y = a + b1 (x1+ b2 (x2).
TL;DR: In this article, the authors determined that the optimum water activities for minimizing a product's degradation rate during storage were determined for prunes and raisins to be about 0.1.
Abstract: Moisture sorption isotherms were determined for raisins and prunes, with raisins producing hysteresis at the lower and higher ends of the curves. Maturity of the fresh fruit influenced the sorption isotherms but not storage time. Optimum water activities for minimizing a product's degradation rate during storage were determined for prunes and raisins to be about 0.1.
TL;DR: In this article, the use of other calcium salts (calcium chloride, calcium lactate, calcium acetate, calcane, calcium carbonate), and two noncalcium compounds (glucono-δ-lactone and acetic acid) was investigated.
Abstract: One of the delicate steps in the preparation of soybean curd is the addition of a salt to precipitate soy protein. The commonly employed salt is calcium sulfate. In this study, the use of other calcium salts (calcium chloride, calcium lactate, calcium acetate, calcium carbonate, calcium phosphate, calcium hydroxide, calcium gluconate) and two noncalcium compounds (glucono-δ-lactone and acetic acid) was investigated. The result showed that soy protein was precipitated by calcium chloride, calcium lactate, calcium acetate, calcium gluconate, glucono-δ-lactone, and acetic acid. The amount of chemical added to precipitate soy protein varied depending upon the type of compound used, but in all cases, soy protein was precipitated when the pH of soy milk was at or near 6.0. Calcium acetate and calcium chloride appeared to be good precipitants for soybean curd preparation. The quality and sensory score of the soybean curd prepared from these salts requires less skill than calcium sulfate because of solubility; besides, the amount of the salt needed to precipitate soy protein was less than one-half that of calcium sulfate.
TL;DR: In this paper, two pectinesterase peaks were observed, the same pH and temperature optima (pH 7.5, temp 60°C), almost equal Michaelis constants (0.029, 0.031%) and energy of activation values (5,600 cal mol-1, 5,740 calmol-1) were obtained for the two PLS fractions.
Abstract: Orange pectinesterase was isolated by ammonium sulfate fractionation followed by ion exchange on CM-Sephadex column. Two pectinesterase peaks were observed, The same pH and temperature optima (pH 7.5, temp 60°C), almost equal Michaelis constants (0.029%, 0.031%) and energy of activation values (5,600 cal mol-1, 5,740 cal mol-1) were obtained for the two pectinesterase fractions. Both enzyme fractions were inhibited by EDTA and polygalacturonic acid and were found to cause clarification of orange juice in a pattern similar to that obtained with natural juice. It can be assumed that the two pectinesterase chromatographic entities have similar catalytic properties.
TL;DR: In this article, a differential scanning calorimeter was used to monitor the changes in heat stability of beef protein during processing of meat into sausage batter and found that the presence of NaCl drastically altered the stability to lower the temperature of denaturation.
Abstract: A differential scanning calorimeter was used to monitor the changes in heat stability of beef protein during processing of meat into sausage batter. Neither the mechanical work done nor the presence of fat affected the protein structural stability but the presence of NaCl drastically altered the stability to lower the temperature of denaturation (Td). This effect was partially reversible on dialysis. Rabbit and pork muscle behaved in a similar fashion. The role of salt in decreasing the Td may be critical in the manufacture of batter-type meat products.
TL;DR: In this article, the temperature dependence of the changes of various sensory attributes has been determined with the aid of the cook-value concept, and the results are compared with literature values.
Abstract: For the heat inactivation of microorganisms the temperature dependence is markedly higher than for the changes of sensory or nutritional quality during thermal processing. With the aid of the cook-value concept, the temperature dependence of the changes of various sensory attributes has been determined. Fish, meat, and vegetable products were processed in thin cans to different quality levels at different temperatures. Values from sensory analysis and color measurements were used to determine the rates of quality changes, and their temperature dependence, which ranged from 13–34°C (average 23°C) for a tenfold shift in the rate of quality changes. The results are compared with literature values. Applications of the results are discussed.
TL;DR: In this article, a model for the prediction of the fish salting process is developed; the same includes: (1) NaCl/water equilibrium in muscle for the processing of fish, with and without cuts, and (2) kinetics of salt penetration and water output and the relationship between the specific rate constants.
Abstract: A model for the prediction of the fish salting process is developed; the same includes: (1) NaCl/water equilibrium in muscle for the processing of fish, with and without cuts, and (2) kinetics of salt penetration and water output and the relationship between the specific rate constants. This model allows for the explanation of the empirical correlations found in the literature such as those of Crean (relationship between water and NaCl percentages) and those of Levanidov (relationship of the weight variations). The model has been empirically checked with anchovy (Engraulis anchoifa), Fueguine sardine (Clupea fueguensis), patagonian haddock (Egleginops maclovinus) and with published data on herring (Clupea harengus), cod (Gadus morhua), swordfish (Xhipias gladius), hake (Merluccius huhbsi), and Black sea anchovy (Engraulis encrasicholus ponticus).
TL;DR: In this article, commercial chocolate products were analyzed for theobromine and caffeine content by High Performance Liquid Chromatography, levels in 22 samples of chocolate liquor averaged 1.22% theobrome and 0.21% caffeine.
Abstract: Commercial chocolate products were analyzed for theobromine and caffeine content by High Performance Liquid Chromatography, Levels in 22 samples of chocolate liquor averaged 1.22% theobromine and 0.21% caffeine. Commercial cocoas contained, on the average, 1.89% theobromine and 0.21% caffeine. Sweet chocolate averaged 0.46% theobromine and 0.07% caffeine, while milk chocolate averaged 0.15% theobromine and 0.02% caffeine. Hot cocoa (chocolate) beverages averaged 65 mg of theobromine and 4 mg of caffeine per 5 ounce serving and chocolate milk prepared from a variety of cocoa-sugar mixes averaged 58 mg of theobromine and 5 mg of caffeine per 8 ounce serving. Theobromine and caffeine levels varied widely in individual samples within the product categories examined. Also, the ratio of theobromine to caffeine varied widely among different chocolate liquors ranging from a low of 2.5:1 to a high of 23.0:1.