Showing papers in "Journal of Food Science in 1987"
TL;DR: In this paper, high performance liquid chromatography analysis of the phenolics in apples showed that the types of phenolic compounds in all cultivars were similar and that no one particular compound could account for the differences observed in browning.
Abstract: Polyphenoloxidase (PPO) activity and polyphenol concentrations decreased during maturation and remained relatively constant during cold storage. However, there was no set pattern of changes in degree of browning during maturation and cold storage. Not all cultivars showed the same relationship between degree of browning and enzyme activity. In some cultivars (Classic Delicious, RI Greening, McIntosh and Cortland), PPO activity was directly related to degree of browning while in others (Empire, Rome and Golden Delicious), degree of browning was related more to phenolic concentration. High performance liquid chromatography analysis of the phenolics in apples showed that the types of phenolic compounds in all cultivars were similar and that no one particular compound could account for the differences observed in browning.
449 citations
TL;DR: Gelatinization characteristics of laboratory-isolated and commercial corn starch were compared by differential scanning calorimetry (DSC) before and after being annealed at sub-gelatinization temperatures in excess water as mentioned in this paper.
Abstract: Gelatinization characteristics of laboratory-isolated and commercial corn starch were compared by differential scanning calorimetry (DSC) before and after being annealed at subgelatinization temperatures in excess water. Prior to annealing, commercial corn starch has a relatively narrow gelatinization range, with a peak temperature at 71°C. Starches isolated in the laboratory have wide gelatinization ranges and lower peak temperatures. After annealing, commercial starch showed little change in gelatinization characteristics, whereas laboratory starches all had narrowed gelatinization ranges, higher peak temperatures, and increased gelatinization enthalpy, indicating changes in the internal structure of the starch granules. This demonstrates that the wet-milling process anneals corn starch during the isolation procedure.
321 citations
TL;DR: The microsomal lipid peroxidation system of flounder muscle was characterized as to response to temperature, cofactor requirements, inhibitors, and activators, and the enzyme-catalyzed reaction had a ratelimiting step prior to the formation of lipid hydroperoxides.
Abstract: The microsomal lipid peroxidation system of flounder muscle was characterized as to response to temperature, cofactor requirements, inhibitors, and activators. The enzyme-catalyzed reaction had a ratelimiting step prior to the formation of lipid hydroperoxides. The KM for NADH of the enzymic system in the presence of 0.1 mM ADP was approximately 1 μM. In the presence of Fe+3 both cysteine and ascorbate also catalyzed lipid peroxidation. While neither NADH nor ADP had an effect in the presence of ascorbate-Fe+3, NADH stimulated the cysteine-Fe+3 oxidation and ADP completely inhibited it. Inhibitor studies indicated that it was a free radical reaction, an -SH group was involved and O2 reduction products and singlet oxygen participated.
313 citations
TL;DR: In this paper, top loin steaks from strip loins selected from 700 beef carcasses representing seven degrees of marbling were randomly assigned to untrained consumers (n = 180 per city) in San Francisco, Philadelphia and Kansas City.
Abstract: Top loin steaks from strip loins selected from 700 beef carcasses representing seven degrees of marbling (Slightly Abundant through Traces) were randomly assigned to untrained consumers (n = 180 per city) in San Francisco, Philadelphia and Kansas City. Statistical analyses revealed a significant marbling level x city interaction. As marbling level decreased from Slightly Abundant to Traces, consumers in San Francisco and Kansas City gave consistently high ratings that were only slightly reduced as marbling was decreased. Consumers in Philadelphia rated steaks with high marbling the same as those from the other cities, but ratings were sharply reduced as marbling decreased. Separate markets might need to be identified to more effectively reflect differences in consumers’ tastes among and within geographic areas of the United States.
274 citations
TL;DR: Reflectance procedures were developed to measure the extent of enzymatic browning at cut surfaces and in the raw juice of apple and pear fruits as mentioned in this paper, and the suitability of these procedures for evaluating the effectiveness of browning inhibitors was demonstrated with SO2 and ascorbic acid treatments.
Abstract: Reflectance procedures were developed to measure the extent of enzymatic browning at cut surfaces and in the raw juice of apple and pear fruits. Reflectance L and a measurements, made at transversely cut surfaces of plugs bored from fruit halves, were linear or bilinear with log time and related to the extent of browning in six apple cultivars. With apple and pear juices, tristimulus values changed linearly with time in samples undergoing browning. Differences between initial and final tristimulus values were better indices of browning than the slopes of time curves. The suitability of these procedures for evaluating the effectiveness of browning inhibitors was demonstrated with SO2 and ascorbic acid treatments.
206 citations
TL;DR: Differential scanning calorimetry was used to determine the thermal transitions in fresh and freeze-dried strawberries and the moisture dependence of these transitions in this article, and the melting of ice in strawberries was similar to that in sugar solutions and fruit juices.
Abstract: Differential scanning calorimetry was used to determine the thermal transitions in fresh and freeze-dried strawberries and the moisture dependence of these transitions. The freeze-dried strawberry samples had a glass transition at 30-6O”C, and the melting endotherm of the dried products was similar to that for freeze-dried sugars. The glass transition temperature of humidified samples was a linear function of the water activity; it decreased with increasing moisture content. Ice was found to melt at a moisture content of 21.4% or above. The melting of ice in strawberries was similar to that in sugar solutions and fruit juices.
194 citations
TL;DR: In this paper, a survey of fresh and commercially processed fruit and vegetable products indicated that the greatest percentage of isomers was found in processed foods (20.1-54.0%).
Abstract: Resolution of cis-trans alpha- and beta-carotene isomers was achieved using a rapid (30 min) high-performance liquid chromatography method employing a slurry-packed calcium hydroxide column. The isomers found in fruit and vegetable products were identical to those formed through iodine catalyzed isomerization of carotene solutions. A survey of fresh and commercially processed fruit and vegetable products indicated that the greatest percentage of isomers was found in processed foods (20.1–54.0%). Of the fresh products surveyed, cis-isomers were found in plums, nectarines and peaches, and no cis-isomers were detected in sweet potatoes, carrots and tomatoes; however, all fresh green vegetables contained from 19.6–28.3% monocis-isomers.
188 citations
TL;DR: Hereford yearling steers were alloted to one of three pasture systems: tall fescue, smooth bromegrass- red clover or orchardgrass-red clover and serially slaughtered at 0, 56, 84 and 112 days, with major differences between volatiles from fat of forage-fed compared to grain-fed steers.
Abstract: Hereford yearling steers (N= 144) were alloted to one of three pasture systems: tall fescue, smooth bromegrass-red clover or orchardgrass-red clover. After the grazing period, steers were finished in drylot and then serially slaughtered at 0, 56, 84 and 112 days. Carcass quality grades and yield grade numbers increased when steers were fed grain up to 112 days. Tenderness of loin steaks increased up to 84 days, after which no improvements were observed. Sensory panel scores for grassy flavor of steaks and ground beef decreased up to 112 days. Fifty-three compounds were identified in the volatiles of melted subcutaneous fat by direct sampling-gas chromatography/mass spectro-metry. The major differences between volatiles from fat of forage-fed compared to grain-fed steers were the higher concentrations of 2,3-octanedione and various diterpenoids present in the samples of the forage-fed animals.
176 citations
TL;DR: In this article, the utility of the phytate/zinc molar ratios for predicting zinc bioavailability from processed soybean foods was investigated, where weight gain and bone zinc accumulation in rats fed various soy protein products were plotted against the calculated molar ratio.
Abstract: The utility of the phytate/zinc and phytate × calcium/zinc molar ratios for predicting zinc bioavailability from processed soybean foods was investigated Weight gain and bone zinc accumulation in rats fed various soy protein products were plotted against the calculated molar ratios The phytate × calcium/zinc ratio was a better predictor of zinc bioavailability in similarly processed products than was the phytate/ zinc ratio However, in some cases the phytate × calcium/zinc ratio was not effective since some processing procedures apparently altered binding of phytic acid to minerals and other food components
175 citations
TL;DR: In this paper, the character notes used by a trained sensory panel to describe warmed-over flavor (WOF) were cardboardy, rancid, stale, and metallic, and the compounds usually associated with lipid oxidation reactions could be used as marker compounds to follow the development of WOF.
Abstract: Raw, freshly cooked, stored and recooked beef muscle samples were assessed by chemical, instrumental and sensory methods of analyses for flavor quality, with particular emphasis on warmed-over flavor (WOF). The character notes used by a trained sensory panel to describe WOF were cardboardy, rancid, stale, and metallic. Samples analyzed by direct gas chromatography utilizing either packed or fused silica capillary columns showed that compounds usually associated with lipid oxidation reactions could be used as marker compounds to follow the development of WOF. Of the many compounds that appeared to be markers, hexanal and 2,3-octanedione as well as total volatiles showed a highly significant degree of correlation when compared to sensory scores and 2-thiobar bituric acid (TBA) numbers. Many of the volatile compounds that were identified in WOF meat samples were also found in the distillates prepared for the TBA reaction.
171 citations
TL;DR: In this paper, water holding and oil absorption capacities increased in proportion to protein contents of the flour, protein fraction, and isolate of each legume, including soybean flour and isolate, but oil emulsification properties were uniformly high among all products.
Abstract: Field pca and faba bean proteins are rich sources of lysine, and air classification of the pin milled flours essentially doubled the protein contents in the protein fractions. The proteins in these flours and protein fractions were highly soluble at acid pH and exhibited only a narrow range of insolubility at pH 4–5. Water holding and oil absorption capacities increased in proportion to protein contents of the flour, protein fraction, and isolate of each legume, including soybean flour and isolate, but oil emulsification properties were uniformly high among all products. The protein fractions exhibited excellent whipp-ability and foam stability compared to soybean controls, and their promising functional properties suggested potential applications in meat emulsions, beverages and bakery products.
TL;DR: Expanded tables for these multiple comparison procedures (involving the “all treatments” and “treatments versus control” comparisons) were presented to accomodate the range of panelists and samples usually encountered in sensory evaluation experiments involving ranked data.
Abstract: Multiple comparison procedures involving Friedman rank sums for the analysis of ranked data have recently been proposed as alternatives to tests developed by Kramer. Expanded tables for these multiple comparison procedures (involving the “all treatments” and “treatments versus control” comparisons) were presented to accomodate the range of panelists and samples usually encountered in sensory evaluation experiments involving ranked data.
TL;DR: In this paper, the effects of chlorophyll and β-carotene on the oxidation stability of purified olive oil were studied by a combination of measuring peroxide value and oxygen disappearance in the headspace of sample bottles by gas chromatography.
Abstract: Virgin olive oil was purified by silicic acid column chromatography to remove non-triglyceride components. The effects of chlorophyll and β-carotene on the oxidation stability of purified olive oil were studied by a combination of measuring peroxide value and oxygen disappearance in the headspace of sample bottles by gas chromatography. Chlorophyll in the purified oil acted as a photosensitizer for singlet oxygen formation under light. β-carotene minimized lipid oxidation of purified oil under light storage by its light-filtering effect. Experiments clearly suggested that singlet oxygen was mainly responsible for the photooxidation of the oil containing chlorophyll.
TL;DR: In this article, the authors showed that reducing the particle size of AACC wheat bran decreased water-holding capacity due to the collapse of its fiber matrix, and that the amount of water held by oat bran and micro-crystalline cellulose was increased by reducing particle size.
Abstract: Reducing the particle size of AACC wheat bran decreased water-holding capacity, due, in part, to the collapse of its fiber matrix. Physical structure of commercial oat bran collapsed during manufacture and further grinding had limited effect. Physical structure of microcrystalline celluloses and guar gums did not differ between product types. The amount of water held by oat bran and microcrystalline cellulose was increased by reducing particle size. Water binding properties of guar gum were not affected. Physical structure of dietary fiber must be considered if water-binding properties are to be useful predictors of stool bulking efficiency.
TL;DR: This article found that low-fat frankfurters were darker, redder, less blue in color, drier and more resistant to shear than high-fat ones, and that lowfat franks containing 1.5% salt had a softer texture than those containing 2.0 or 2.5%.
Abstract: Frankfurters were manufactured from preblended (PB) or nonpreblended (NPB) meats to contain traditional and reduced levels of salt (1.5, 2.0, or 2.5%) and/or fat (17%= low; 25%= high). Emulsions stability, color, Kramer shear and palatability were evaluated. Salt had a positive effect on emulsion stability (p<0.05). Low-fat frankfurters were darker, redder, less blue in color, drier and more resistant to shear than high-fat frankfurters. Low-fat franks containing 1.5% salt had a softer texture than those containing 2.0 or 2.5% salt. Preblending did not affect textural properties. With modification of the formulations, low fat-low salt franks can be manufactured.
TL;DR: In this paper, three potato cultivars (Norchip, Simcoe and Onaway) were evaluated for sugar content and chip color during growth and harvest, two weeks prior and two weeks after foliar senescence, and stored under various time-temperature regimes and upon reconditioning.
Abstract: Two potato cultivars (Kennebec and Simcoe) and one selection (ND 860–2) were stored for 3 months at 4°, 9° and 11°C. ND 860–2 had the lowest sugar content at all storage temperatures, produced the lightest colored chips and was the only sample which gave acceptable colored chips directly from 4°C storage. In another study, three potato cultivars (Norchip, Simcoe and Onaway) and one selection (ND 860–2) were evaluated for sugar content and chip color during growth and harvest, two weeks prior and two weeks after foliar senescence, and stored under various time —- temperature regimes and upon reconditioning. ND 860–2 generally had the lowest levels of fructose, glucose and sucrose and Onaway had the highest. Storage at 5°C resulted in increases in the three sugars for all tubers, sucrose showing the most notable increase. ND 860–2 was the only sample to consistently produce acceptable colored chips directly from 5°C.
TL;DR: In this article, the effects of copper sulfate and proteose-peptone on egg white foams were studied to detect differences between foams produced by different proteins, such as sodium caseinate, milk protein isolate and whey protein.
Abstract: A whipping method for the measurement of overrun and foam stability was developed. Using this method the characteristic foams formed by the following proteins were studied: sodium caseinate, milk protein isolate and whey protein. The method was able to detect differences between foams produced by different proteins. The effects of copper sulfate and proteose-peptone on egg white foams were studied to show the reliability of the method. It was demonstrated that the addition of ImM copper sulfate stabilized (p < 0.05) foams made from both fresh and powdered egg white. Addition of proteose-peptone (0.05% and 0.1%) reduced the overrun and destabilized egg white foams.
TL;DR: In this paper, the effects of freezing, thawing, cooking and drying on carotene retention of carrots, broccoli and spinach were evaluated and relative differences in carotenes retention among these vegetables were compared.
Abstract: Effects of freezing, thawing, cooking and drying on carotene retention of carrots, broccoli and spinach were evaluated. Relative differences in carotene retention among these vegetables were compared. Dehydration, regardless of drying method, significantly reduced carotene in these vegetables. Carotene contents of fresh, vacuum and microwave dried samples for carrots, broccoli and spinach were 989, 459, 368; 106, 43, 40; and 455, 325, 314 μg/g, respectively. Lag time after thawing decreased mean carotene of vegetables significantly in a quadratic manner. Degradation of carotene was severe 6 hr after thawing, Cooking did not affect carotene and cooked samples contained 2.0, 2.9, and 1.2 times more carotene than the respective dehydrated vegetables. Destruction of carotene was relatively lower when initial concentrations were low.
TL;DR: The muscle showed full rigor when ATP completely disappeared and lactic acid attained the maximum plateau (40–50 μmol/g), and correlated well with the decrease of ATP.
Abstract: Live specimens of the plaice Paralichthys olivaceus were spiked at the brain, stored at various temperatures ranging from 0° to 20°C and examined for changes in rigor tension and ATP degradation in the muscle. The ATP degradation rate was clearly slower at 5–15°C than at WC, resulting in retardation of rigor- mortis onset at the former temperatures. Lactic acid accumulation in the muscle correlated well with the decrease of ATP. The muscle showed an ATP concentration of 3 μmol/g and “rigor index” (full rigor = 100%) at 30% when lactic acid increased up to 30 μmol/g at most storage temperatures. The muscle showed full rigor when ATP completely disappeared and lactic acid attained the maximum plateau (40–50 μmol/g).
TL;DR: In this paper, the authors used an experimental high temperature fluidized bed (HTFB) dehydrator to dry Rabbiteye blueberries and evaluated the properties of the dried product using a probabilistic model.
Abstract: Rabbiteye blueberries were dried using an experimental high temperature fluidized bed (HTFB) dehydrator and the properties of the dried product were evaluated. 15 m/sec air velocity was required for fluidization and at 170°C the moisture content (MC in kg water/kg dry matter) of thawed blueberries was reduced from 5.8 to 0.7 after 8 min. After osmotic dehydration in sucrose, MC was 1.3, and 4 min in the HTFB drier at 150°C reduced MC to 0.28. Reduction of water activity to 0.5 after HTFB required cabinet drying at 60°C and 4 m/ set for 2.13 and 2.75 hr for the untreated and osmotically dehydrated berries, respectively. HTFB simultaneously dried and puffed the berries, resulting in reduced bulk density compared to berries produced using conventional drying. Osmotic dehydration prior to HTFB imparted a raisin-like texture to the product.
TL;DR: Functional properties of two corn germ protein (CGP) preparations, supercritical CO2 (SC—CO2) and hexane defatted, were studied in model systems using response surface methodology to identify the different functional properties of hexane CGP.
Abstract: Functional properties of two corn germ protein (CGP) preparations, supercritical CO2 (SC—CO2) and hexane defatted, were studied in model systems using response surface methodology. The protein preparations had different fat and moisture content. The SC—CO2 CGP was whiter (1), less red (a) and less yellow (b) in color measurement than hexane CGP. Temperature of incubation influenced the functionality of the SC—CO2 and hexane-defatted CGP in model system. SC-CO2 CGP had higher fat binding and water retention than hexane CGP. Fat binding decreased during the heat treatment for SC-CO2 CGP. Water retention in both preparations increased as temperature increased to 70°C. The different functional properties of hexane CGP may be due to the extent of protein denaturation.
TL;DR: In this article, a solid-state fermentation method was developed for the production of citric acid from kiwifruit peel by Aspergillus niger NRRL 567.
Abstract: A solid-state fermentation method was developed for the production of citric acid from kiwifruit peel by Aspergillus niger NRRL 567. This method produced about 100g citric acid per kg of kiwifruit peel fermented in the presence of 2% methanol at 30°C in 4 days. The yield was more than 60% based on the amount of fermentable sugar consumed.
TL;DR: In this article, rheological properties of dilute and concentrated solutions of water-soluble, alcohol-precipitated tomato pectins from hot break and cold break tomato paste as well as commercially available apple and citrus pectin were studied.
Abstract: Rheological properties of dilute and concentrated solutions of water-soluble, alcohol-precipitated tomato pectins from hot break and cold break tomato paste as well as alcohol-precipitated commercially available apple and citrus pectins were studied. Superposition of rheological data was possible when nsp was plotteds vs c[η] and when η/ηo was plotted vs τγ The slope of nsp vs cMw plot and the limiting slope of η/η0 vs (τγ suggested that citrus, apple and hot break tomato pectin had random coil conformation while cold break tomato pectin had a more rigid conformation. Tomato processing had significant influence on the chain length and rheological properties of tomato pectins.
TL;DR: In this article, a zero-order reaction model was used to describe the behavior of fructose-glycine solutions, but for the other sugars a fractional-order (∼ 0.5) kinetic model was necessary.
Abstract: Sugar- (fructose, xylose, glucose, lactose, maltose, sucrose) glycine solutions of water activity adjusted to 0.90 (by adding NaCI) were heated at 45–65°C. The behavior of fructose-glycine solutions was well described by a zero-order reaction model, but for the other sugars a fractional-order (∼ 0.5) kinetic model was necessary. Activation energies for glucose, fructose and sucrose systems were 25.7, 29.3 and 36.6 kcah/mole, respectively. At pH 6 the descending order for color development was xylose > glucose > fructose > lactose > maltose > sucrose; at pH lower than 6 fructose browned faster than glucose. The role of hydrolysis of sucrose as related to Maillard's browning of heated sucrose-glycine solutions was studied. Caramelization browning seemed to contribute noticeably to total color development only in fructose-glycine solutions.
TL;DR: In this article, carrageenan was used to increase the rigidity and hardness of batters with either 0.5% or 1% iota CARRAGEENAN.
Abstract: Meat batters containing either 0.5% or 1% iota carrageenan (IC, kappa carrageenan (KC) or xanthan gum (XG) were investigated. Rigidity changes during heating and Instron texture profile analysis indicated textural properties of batters. All treatments exhibited a decrease in water-holding ability (WHA) from 55–70°C. Addition of IC increased WHA, rigidity at 70°C, force-to-fracture and true shear strain. KC increased rigidity at 70°C and was most effective at increasing hardness. XC decreased all textural parameters measured. Gums were specific in affecting textural and WHA properties.
TL;DR: The total fat and fatty acid compositional data are reported herein for 41 different species of fish that are mostly found in the coastal waters of the Eastern United States.
Abstract: An awareness of the protective roll of n-3 polyunsaturated fatty acids against development of cardiovascular disease has prompted the promotion of fish consumption. It is assumed that those fish rich in polyunsaturated fat and particularly those having high ratios of n-3 to n-6 polyunsaturated fatty acids would confer the most benefit. The total fat and fatty acid compositional data are reported herein for 41 different species of fish that are mostly found in the coastal waters of the Eastern United States.
TL;DR: In this paper, the auditory and oral crispness of potato chip products was measured using a combination of acoustical and force-deformation measurements, which provided an excellent measure of oral chip crispness.
Abstract: The auditory (sound only) and oral (normal biting and chewing) crispness of five different potato chip products, each adjusted to two moisture contents, were measured. Instrumental acoustical and force-deformation measurements were made on these same samples and compared with the sensory crispness measurements. Oral crispness judgments appeared to be made on the basis of both auditory and oral tactile sensations, since auditory crispness was not highly correlated to oral crispness. A combination of acoustical and force-deformation measurements provided an excellent measure of oral chip crispness.
TL;DR: In this article, the influence of the vicilin/legumin ratio on the efficiency of pea isolates as emulsifying agents was studied and the results were discussed by reference to the interface adsorption behaviors of these proteins.
Abstract: Emulsifying properties of purified pea globulins and of vicilin-legumin mixtures were evaluated through their emulsifying capacity, emulsifying activity index and stability of the resulting emulsions. The results were discussed by reference to the interface adsorption behaviors of these proteins. The influence of the vicilin/legumin ratio on the efficiency of pea isolates as emulsifying agents was also studied. Vi-cilin which has been shown to be more surface active at air/water and dodecane/water interfaces, led also, in both cases, alone or mixed, to better emulsifying properties than legumin. The globulin composition of the isolates did not completely explain their emulsifying behaviors.
TL;DR: In this article, the intrinsic viscosity of tomato serum determined from the slopes of three equations were not identical, but they showed common trends, such as lower viscosities of serums from concentrates obtained by evaporation of juice and reverse osmosis concentration of serum.
Abstract: Magnitudes of intrinsic viscosity of tomato serum determined from the slopes of three equations were not identical, but they showed common trends. Intrinsic viscosities of serums from concentrates obtained by evaporation of juice were lower than those obtained by evaporation of serum and reverse osmosis concentration of serum. Their magnitudes also were lower for serums from diluted and sheared concentrates.
TL;DR: In this paper, the extruded products were evaluated for extent of starch gelatinization and the results indicated that the degree of gelatinization decreased with increasing moisture content but increased with increasing temperature.
Abstract: Ordinary corn (30% amylose) and waxy corn (1% amylose) were extruded at 17.8, 20, 30, 40 and 42.2% product moisture contents (d.b.) and extruder barrel temperatures of 116°, 120°, 140°, 160° and 164°C. Screw speeds of 93.5, 100, 130, 160 and 166.5 rpm were used to generate different residence times. The extruded products were evaluated for extent of starch gelatinization. Results indicate that the degree of gelatinization decreased with increasing moisture content but increased with increasing temperature. Starch gelatinization exhibited pseudo-zero-order reaction kinetics with higher rate constants for waxy corn than for high amylose corn. The rate constants decreased with decreasing temperature.