Showing papers in "Journal of Food Science in 1989"
TL;DR: In this article, a systematic approach that allows the correlation of the response of a Time-Temperature Indicator (TTI) to the consumed and remaining shelf life of a food product exposed to the same variable temperature conditions was developed.
Abstract: A systematic approach that allows the correlation of the response of a Time-Temperature Indicator (TTI) to the consumed and remaining shelf life of a food product exposed to the same variable temperature conditions was developed. The approach was based on kinetic principles and is applicable to a TTI-food system without necessitating side by side testing. The applicability of three major TTI types to the developed scheme was studied. Experiments under several isothermal conditions were conducted and kinetic parameters for the three TTI were determined. All TTI showed an Arrhenius temperature dependence and their calculated activation energies ranged from 10 to 40 kcal/mol.
353 citations
TL;DR: Pigment and lipid oxidation was investigated in fresh ground sirloin from control and vitamin E-supplemented (370 I.U/head/day) Holstein steers as discussed by the authors.
Abstract: Pigment and lipid oxidation was investigated in fresh ground sirloin from control and vitamin E-supplemented (370 I.U./head/day) Holstein steers. Alpha-tocopherol levels were higher (P<0.05) in muscle from supplemented animals than from controls. During 6 days storage at 4°C, metmyoglobin accumulation and lipid oxidation (TBA) were greater (P<0.05) in beef from control versus supplemented animals. TBA value and % metmyoglobin were highly correlated in the control (r = 0.91) and supplemented (r = 0.72) groups. TBA values of cooked sirloin slices subsequently stored for 2 days at 4°C, and for frozen ground sirloin patties stored at -18°C for 1.5 and 3 months, were lower (P<0.05) in beef from supplemented animals than from controls. Meat which contained in excess of ca. 0.3 mg α-tocopherol/100 g tissue displayed the least oxidation of both pigments and lipids.
339 citations
TL;DR: In this paper, gas-liquid chromatography was used to determine the essential oil compositions of thyme, cumin, clove, caraway, rosemary, and sage, and the antifungal potential of the oils against Aspergillus parasiticus was investigated.
Abstract: Gas-liquid chromatography was used to determine the essential oil compositions of thyme, cumin, clove, caraway, rosemary, and sage. The basic components of these oils were thymol, cumin aldehyde, eugenol, carvonc, borneol and thujonc, respectively. The antifungal potential of the oils against Aspergillus parasiticus were investigated. The essential oils caused complete inhibition of both mycelial growth and aflatoxin production. The effectiveness followed the sequence: thyme > cumin > clove > caraway > rosemary > sage. The major components of the essential oils produced an inhibitory effect at minimum inhibitory concentrations equal to those obtained with the oils.
298 citations
TL;DR: In this article, the authors investigated the effects of pH (5.50-7.00), sodium chloride concentration (0.0-3.0%), and sodium tripolyphosphate concentration ( 0.0 and 0.5%) on the percent myoglobin denatured (PMD) in beef, pork and turkey muscle when heated to temperatures between 55 and 83°C.
Abstract: This study investigated the effects of pH (5.50–7.00), sodium chloride concentration (0.0–3.0%), and sodium tripolyphosphate concentration (0.0 and 0.5%) on the percent myoglobin denatured (PMD) in beef, pork and turkey muscle when heated to temperatures between 55 and 83°C. At most temperatures studied, the presence of sodium chloride and sodium tripolyphosphate increased the PMD. In contrast, high pH markedly decreased the PMD (P<0.05). The effect of pH on PMD was similar for all three species studied and, in all cases, was sufficient to produce obvious color differences in the cooked muscles.
273 citations
TL;DR: Sliced strawberries (cvs.‘Pajaro’ and 'G-3′) and partially ripe pears (cv. ‘Bartlett’) were dipped in various solutions (citric acid, ascorbic acid, and/or calcium chloride) and stored in air or in controlled atmospheres (CA) for 7 days at 2.5°C followed by one day at 20°C as discussed by the authors.
Abstract: Sliced strawberries (cvs.‘Pajaro’ and 'G-3′) and partially ripe pears (cv.‘Bartlett’) were dipped in various solutions (citric acid, ascorbic acid, and/or calcium chloride) and stored in air or in controlled atmospheres (CA) for 7 days at 2.5°C followed by one day at 20°C. Fruit slices respired at a higher rate than whole fruits at both temperatures. CA storage suppressed respiration and ethylene production rates of sliced fruits. Firmness of strawberry and pear slices was maintained by storage in air + 12% CO2 and in a 0.5% O2 atmosphere, respectively, or by dipping in 1% calcium chloride. These treatments also resulted in lighter colored pear slices than the air control treatment.
226 citations
TL;DR: Survivor curves showed that cell death occurred in this pressure range and increased as pressure increased and was greater in buffer than in the chicken medium.
Abstract: Salmonella senftenberg 775W, a heat-resistant strain (D57.5°C= 15.0 min) and Salmonella typhimurium ATCC 7136, a heat-sensitive strain (D57.5°C=3.0 min), were subjected to hydrostatic pressures of 2,380 to 3,400 atmospheres (atm) at 23°C in phosphate buffer (63 mM, pH 7.0) and chicken medium (strained baby food). Survivor curves showed that cell death occurred in this pressure range and increased as pressure increased. Death was greater in buffer than in the chicken medium. S. senftenberg 775W was more sensitive to pressure than S. typhimurium 7136. Injury occurred over the range of pressures for both species. Recovery at 37°C was possible following pressurization for salmonellae in chicken but not in buffer.
216 citations
TL;DR: In this paper, the effect of concentration and temperature on thermophysical properties of clarified apple juice was studied, including density, viscosity, specific heat, and thermal conductivity.
Abstract: Effect of concentration and temperature on thermophysical properties of clarified apple juice was studied. Density, viscosity, specific heat, and thermal conductivity were measured at different conditions, ranging from 20 to 90oC and 12 to 70oBrix. Experimental data were related to the corresponding properties of water and compared with the behavior of sugar solutions. The results obtained were used to derive mathematical models and correlations for predicting these properties as a function of both concentration and temperature.
201 citations
TL;DR: In this article, the composition, solubility, foamability and moisture sorption characteristics of Flax seed (Linwn usitatissimum L.) mucilage were determined.
Abstract: Flax seed (Linwn usitatissimum L.) mucilage was prepared by extraction of seeds with water followed by evaporation, precipitation with ethanol and freeze drying of extract. Proximate composition, solubility, foamability and moisture sorption characteristics were determined. The mucilage contained less carbohydrates, more minerals and more protein than commercial locust bean and guar gums. Its solubility, however, was higher than locust bean and guar gums, and lower than gum arabic. Flax seed mucilage exhibited good foam stability properties in aqueous solutions at 1.0% (w/v). Very diluted solutions exhibited Newtonian-like behavior while shear thinning was shown at concentrations above 0.2% (w/v). The viscosity was maximum at a pH range 6.0–8.0 and it was reduced in solutions containing NaCl.
201 citations
TL;DR: An edible composite film of lipid and cellulose ethers was developed and appraised as a barrier to moisture vapor transmission in this paper, which was comprised of a matrix of methylcellulose, hydroxypropyl meth-ylcelluloses and saturated C16 and C18 fatty acids, with a thin layer of white beeswax laminated to the surface.
Abstract: An edible, composite film of lipid and cellulose ethers was developed and appraised as a barrier to moisture vapor transmission. The film was comprised of a matrix of methylcellulose, hydroxypropyl meth-ylcellulose and saturated C16 and C18 fatty acids, with a thin layer of white beeswax laminated to the surface. The edible film effectively retarded transport of moisture at water activities (aw) up to at least 0.97 and maintained good barrier properties even when the aw on the low-humidity side of the film was relatively high. The apparent activation energy for water vapor transmission through the edible film was 14.2 ± 2.5 kcal/mole. Electron microscopy revealed the importance of lipid morphology in determining moisture resistance lipid-base films.
194 citations
TL;DR: In this paper, the authors evaluated the effect of removing subcutaneous fat on lipid retention during broiling of pork chops and found that fat removal was not a tenable explanation for reports of lipid retention exceeding 100% during cooking.
Abstract: Conventionally trimmed (0.6 cm) and completely trimmed (0 cm) prok chops were used to evaluate the effect of removing subcutaneous fat on lipid retention during broiling of pork. Composition of the lean portion of cooked chops was not affected by removal of external fat before cooking. Conventional chops contained 4.4% either extractable lipid and completely trimed chops contained 4.3%. Lipid retention was also the same at 94–99%. Recovery of moisture, protein, and lipid was 98–99%, using ether extraction or chloroform:methanol extraction. Therefore, the concept of lipid migration during cooking was not a tenable explanation for reports of lipid retention exceeding 100% during broiling of pork chops typical of those available to consumers.
189 citations
TL;DR: In this paper, a method was developed for determination of O2 consumption as a function of the O2 concentration by mathematical characterization of depletion by a tomato fruit in a closed system with time.
Abstract: A method was developed for determination of O2 consumption as a function of O2 concentration by mathematical characterization of O2 depletion by a tomato fruit in a closed system with time. Mathematical equations were developed describing O2 consumption as a function of O2 concentration for breaker, pink and red tomato fruit and were used to model film permeability characteristics (O2 permeability coefficient, surface area, thickness) as a function of fruit weight to achieve desired sealed package concentrations of O2 in modified atmosphere packages. Equations were also developed to describe the time for initial O2 establishment as affected by void volume. Calculations are presented for optimizing package parameters for tomato fruit.
TL;DR: This paper showed that α-tocopherol significantly improved the oxidative stability of the dark and white broiler meat during refrigerated and frozen storage compared to the broilers fed partially hydrogenated soybean oil (HSBO).
Abstract: Broilers were fed diets containing oils of varying degrees of unsaturation, namely coconut oil, olive oil, linseed oil and partially hydrogenated soybean oil (HSBO), with and without α-tocopherol supplementation. The different oils significantly (P<0.01) affected the fatty acid composition of the neutral lipids and, to a lesser extent, the fatty acid composition of the phopholipids. Fatty acid composition, in turn, influenced the oxidative stability of the meat during refrigerated and frozen storage. Meat from broilers fed olive oil or coconut oil was consistently more stable than meat from the linseed oil group. Dietary supplementation with α-tocopherol significantly (P<0.01) improved the oxidative stability of the dark and white broiler meat during refrigerated and frozen storage compared to meat from the broilers fed HSBO.
TL;DR: In this paper, a high performance liquid chromatographic method was developed for the quantitative analysis of organic acids in dairy products using a reverse-phase C8 column at room temperature, a mobile phase of 0.5% w/v buffer ((NH4)2HPO4 at pH 2.24 with H3, PO4)-0.4% v/v acetonitrile, UV detection at 214 nm and 1.2 mL/min flow rate were utilized.
Abstract: A high performance liquid chromatographic method was developed for the quantitative analysis of organic acids in dairy products. A reverse-phase C8 column at room temperature, a mobile phase of 0.5% w/v buffer ((NH4)2HPO4 at pH 2.24 with H3, PO4)-0.4% v/v acetonitrile, UV detection at 214 nm and 1.2 mL/min flow rate were utilized. Formic, acetic, pyruvic, propionic, uric, orotic, citric, lactic and butyric acids were quantitated for raw milk, yogurt, Blue, Provolone, Port Salut and Quartirolo cheeses. Recoveries greater than 85.3% were observed for all acids.
TL;DR: In this paper, the nitrogen solubility, emulsification, and foaming properties of rice bran protein concentrates were measured over the pH range 2.0 to 10.5 and in three dispersion media including water, 0.1M NaCl (low salt), and 1.0M NaCL (high salt).
Abstract: Rice bran protein concentrates were prepared from full-fat and defatted raw rice bran. Selected functional properties, viz. nitrogen solubility, emulsification properties, and foaming properties were measured over the pH range 2.0 to 10.5 and in three dispersion media including water, 0.1M NaCl (low salt) and 1.0M NaCl (high salt). Below and above the isoelectric pH (4.5) the nitrogen solubility increased. Higher pH enhanced the nitrogen solubility and, thereby, considerably improved the functional properties. In higher salt concentration, nitrogen solubility was reduced which also altered the properties of emulsification and foaming. Multiple regression analysis showed that pH was the primary determinant of nitrogen solubility, emulsification and foaming properties. Multiple regression models including pH, salt concentration and nitrogen solubility as independent variables were found to be more accurate in predicting other functional properties.
TL;DR: A modification of McKellar and Cholette's (1986) colorimetric method for determining lipase activity in reconstituted non-fat dry milk was developed as mentioned in this paper.
Abstract: A modification of McKellar and Cholette's (1986) colorimetric method for determining lipase activity in reconstituted non-fat dry milk was developed. The method uses the color reaction between Fast Blue BB and the β-naphthol (BN) enzymatically cleaved from β-naphthyl cap-rylate (BNC) as a measure of lipase activity. In the modified method, a solvent system is used to clarify the sample rather than extracting the colored product. This modification allows measurement of total sample lipase by excluding centrifugation. In addition, the modified method has greater sensitivity with equal ease of use.
TL;DR: In this paper, the effects of inositol tri-, tetra-, penta-, and hexaphosphates on iron solubility were studied in vitro in a freeze-dried wheat roll and digestion was performed simulating physiological conditions.
Abstract: The effects of inositol tri-, tetra-, penta-, and hexaphosphates on iron solubility were studied in vitro. Pure inositol phosphates (0.125–10 μmol) were added to 1g of freeze-dried wheat roll and digestion was performed simulating physiological conditions. Soluble iron was used as an index of iron bioavailability. The pure inositol phosphate fractions were prepared by hydrolysis of sodium phytate and separation on anion exchange resin. The inositol phosphates were identified and quantified by HPLC. Addition of 10 μmol inositol hexa- and pentaphpsphate reduced iron solubility from 39% (reference) to 0.2% and 6%, respectively, while the same amount of inositol tetra- and tri-phosphate slightly increased the iron solubility. Thus, degradation of inositol hexa- and pentaphosphates seemed to significantly reduce the inhibiting effect on iron availability.
TL;DR: In this paper, it was shown that β-glucosidases were responsible for the production of daidzein and genistein during soaking of soybeans, and that the maximum production of these isoflavone compounds occurred at 50°C and at pH 6.0 depending upon the temperature and pH of the soaking water.
Abstract: Daidzein and genistein, which are responsible for the objectionable flavor of soy milk, increased during the soaking of soybeans, the first step of soy milk manufacturing. The maximum production of these isoflavone compounds occurred at 50°C and at pH 6.0 depending upon the temperature and pH of the soaking water. The production of these substances was strongly inhibited by glucono-δ-lactone which was a competitive inhibitor of β-glucosidascs. It would appear, therefore, that β-glucosidases were responsible for the production of daidzein and genistein during soaking.
TL;DR: This paper evaluated browning inhibitors in raw apple juice and on the cut surface of apple plugs, using quantitative measurements of color changes during storage to assess treatment effectiveness and found that β-cyclodextrin with ascorbic acid (AA), AAP or ascorbyl palmitate were effective in juice but not on cut surfaces.
Abstract: Novel browning inhibitors were evaluated in raw apple juice and on the cut surface of apple plugs, using quantitative measurements of color changes during storage to assess treatment effectiveness. Ascorbic acid-2-phosphate (AAP) and -triphosphate (AATP) showed promise for cut surfaces but were ineffective in juice. Ascorbic acid-6-fatty acid esters showed anti-browning activity in juice. Cinnamate and benzoate inhibited browning in juice but induced browning when applied to cut surfaces. Combinations of β-cyclodextrin with ascorbic acid (AA), AAP or ascorbyl palmitate were effective in juice but not on cut surfaces. Combinations of AA with an acidic polyphosphate were highly effective with both juice and cut surfaces.
TL;DR: The growth parameters for Listeria monocytogenes Scott A at various temperatures, pH values, water activity values, and in different carbohydrates were assessed and optimum growth was defined as shortest generation time.
Abstract: The growth parameters for Listeria monocytogenes Scott A at various temperatures, pH values, water activity values, and in different carbohydrates were assessed. Growth was seen from 4°C through 45°C and at pH values from 4.7 through 9.2. Generation times were calculated for each parameter at which growth was observed. Optimum growth was defined as shortest generation time. L. monocytogenes grew optimally over the temperature range 30–37°C. The optimum pH was 7.0. Growth was demonstrated in solutions of up to 39.4% sucrose (aw of 0.92). Carbohydrate fermentation was variable. Further studies involved examination of growth at optimal water activities (0.97) with suboptimal temperatures and pH values, and at 7.0, with suboptimal temperatures and water activities. Growth was seen when these parameters were combined.
TL;DR: In this article, two formulations consisting of a methylcellulose base layer and a beeswax layer, deposited either from a molten state (Wax-M film) or from an ethanolic solution, were examined for water vapor permeability (WVP), oxygen permeability and other physical properties.
Abstract: Various formulations and methods of fabricating a film consisting of edible hydrocolloids and lipids were investigated. Two formulations consisting of a methylcellulose base layer and a beeswax layer, deposited either from a molten state (Wax-M film) or from an ethanolic solution (Wax-S film), were examined for water vapor permeability (WVP), oxygen permeability and other physical properties. WVP values (g-mil-m−2-day−1-mm Hg−1) for the Wax-M and Wax-S films were 0.5 ± 0.05 and 1.6 ± 0.4, respectively. WVP of the two films did not change significantly after storage for 1 wk at -40°C. Oxygen permeability values (g-cm-cm−2-sec−1-mm Hg−1× 10−12) for the Wax-M and Wax-S films were 0.021 ± 0.002 and 0.007 ± 0.002, respectively. The Wax-M film had a more uniform surface topography than the Wax-S film.
TL;DR: In this article, the effects of dietary tocopherol and oxidized dietary oil on the oxidative stability of membranal lipids in pig muscles and on the oxid stability of pork products during refrigerated and frozen storage were evaluated.
Abstract: The effects of dietary tocopherol and oxidized oil on the oxidative stability of membranal lipids in pig muscles and on the oxidative stability of pork products during refrigerated and frozen storage were evaluated Membrane-bound α-tocopherol stabilized the membranal lipids and reduced the extent of lipid oxidation occurring in pork patties and pork chops during storage Oxidized dietary oil had an adverse effect on the stability of both the membranal lipids and pork products The addition of salt to the pork patties accelerated the oxidative process when the patties were stored under fluorescent light and in the dark
TL;DR: In this paper, the authors used methyl ester content of pectin to investigate the heat degradation mechanism in an aqueous environment, and found that the higher the methyl esters content, the greater the degradation.
Abstract: Chelator-soluble pectin was isolated from carrot under mild conditions and used as a model compound for an investigation of the heat degradation mechanism of pectin in an aqueous environment. Methyl ester content was modified with minimal changes in the polymer size. At pH 6.1 the heated pectin preparation degraded primarily through β-eliminative cleavage of the chain. The higher the methyl ester content the greater the degradation. Evidences also indicated a-small amount of hydrolytic cleavage of glycosidic bonds which was not affected by the presence of the methyl ester content. De-esterification of methyl ester groups proceeded at a faster rate than the eliminative cleavage of the chain; however, under the test conditions, it did not terminate the β-elimination.
TL;DR: In this paper, a mixture of skim milk powder (SMP), a whey protein concentrate (WPC) and fat globules with modified membranes were used for the fabrication of mixed and filled dairy gels.
Abstract: Skim milk powder (SMP), a whey protein concentrate (WPC) and fat globules with modified membranes were used for the fabrication of mixed and filled dairy gels. Firmness and syneresis of pure gels varied broadly with pH and total solids (TS). Mixing SMP and WPC at 10% TS showed synergistic effects on gel firmness, particularly for 50:50 blends, and addition of fat provided further reinforcement. Syneresis of gels and their appearance changed from high and clear to low and turbid, respectively, as the WPC content was increased. Microstructural studies revealed the porous structure of the parent gels, compatability between both protein sources and between fat globules and the protein matrix.
TL;DR: Colorimetric measurements were recorded for sirloin steaks from control and vitamin E-supplemented Holstein steers and color difference between the two treatment groups increased from days 0 to 6 and decreased between days 6 and 8.
Abstract: Colorimetric measurements were recorded for sirloin steaks from control and vitamin E-supplemented (370 I.U./animal/day) Holstein steers. Chroma and Hunter ‘a’ values of steaks from the supplemented group were significantly greater (P&0.01) on days 2, 4, 6, and 8 of 4°C storage. Color difference (ΔE) between the two treatment groups increased from days 0 to 6 and decreased between days 6 and 8.
TL;DR: The concentration of proteolytic products was determined as free amino acids in the water-soluble fraction at two, four, seven and nine months of aging and at two different maturation temperatures (6°C, 15°C).
Abstract: Cheddar cheese was produced with different lactobacilli strains added to accelerate ripening. The concentration of proteolytic products was determined as free amino acids in the water-soluble fraction at two, four, seven and nine months of aging and at two different maturation temperatures (6°C, 15°C). All amino acids increased during ripening and were higher in the Lactobacillus- added cheeses than in the control cheese, and higher in cheeses ripened at 15°C than at 6°C. Glutamic acid, leucine, phenylalanine, valine and lysine were generally in higher proportion in all cheeses. The cheeses with added L. casei-casei L2A were classified as having a “strong Cheddar cheese” flavor after only seven months of ripening at 6°C.
TL;DR: In this paper, two bilayer films, consisting of methylcellulose (MC) and polyethylene glycol 400 in the hydrocolloid layer, and beeswax, either applied molten (Wax-M film) or from an ethanol solution, in the lipid layer, were evaluated as barriers to water vapor (WV) after abusive tests.
Abstract: Two edible, bilayer films, consisting of methylcellulose (MC) and polyethylene glycol 400 in the hydrocolloid layer, and beeswax, either applied molten (Wax-M film) or from an ethanol solution (Wax-S film), in the lipid layer, were evaluated as barriers to water vapor (WV) after abusive tests. The Wax-M film maintained its WV barrier properties better than the Wax-S film after mechanical abuse. The Wax-M film was also evaluated as a moisture barrier when formed-in-place on the surface of brownies. When brownies were stored at 100% relative humidity and 25°C, the Wax-M film significantly (P < 0.05) decreased moisture absorption as compared to that of control samples.
TL;DR: In this article, the reliability of TTI under variable temperature conditions was systematically studied, and three major types of commercial TTI were studied and it was shown that, although some types exhibit a significant history effect, the prediction models can be applied satisfactorily for the variable temperature storage.
Abstract: Application of time temperature indicators (TTI) is based on response information or kinetic models from isothermal testing. The reliability of such models under variable temperature conditions was systematically studied. Nonisothermal experiments of two types were conducted involving prolonged exposures to high temperatures followed by storage at low temperatures to study the “history effect,” and storage at controlled, sinusoidaly varying temperatures. Three major types of commercial TTI were studied. Results showed that, although some types of TTI exhibit a significant “history effect,” the prediction models can be applied satisfactorily for the variable temperature storage.
TL;DR: In this article, the final fat content of beef frankfurters was reduced to 12, 20, and 29% fat levels using beef fat or 60% substitution with peanut oil.
Abstract: Frankfurters were produced at 12, 20 and 29% fat levels using beef fat or 60% substitution with peanut oil. Less emulsion stability, lower smokehouse yield and lower sensory juiciness scores were found as final fat content of beef frankfurters was lowered to 12%. Firmness, darkening of external color, and flavor intensity were enhanced in the low fat product. Frankfurters with 60% fat as peanut oil exhibited comparable emulsion stability and sensory quality parameters with no rancid flavor development over a period of 6 weeks at 4°C. They were as acceptable to sensory panels as the 29% beef fat frankfurters. Substitution of 60% of the beef fat with peanut oil resulted in a product with significantly (P < 0.05) less cholesterol content.
TL;DR: In this paper, the volatile components of crayfish processing waste were analyzed by dynamic headspace/capillary gas chromatography/mass spectrometry and chromatography-coupled aroma perception analysis with simultaneous photoionization detection.
Abstract: Volatile components of crayfish processing waste were analyzed by dynamic headspace/capillary gas chromatography/mass spectrometry and chromatography-coupled aroma perception analysis with simultaneous photoionization detection. One hundred seventeen compounds were identified. The majority of the flavor compounds previously identified in freshly boiled crayfish tail meat and hepatopancreas also were detected in crayfish waste. Many areas in the headspace profile contained good nutty, green woody, sweet fruity and very desirable salty meaty aromas, indicating the presence of important crayfish flavor components in the sample.