Showing papers in "Journal of Food Science in 1984"
TL;DR: In this paper, essential oils from plants were screened for inhibitory effects on 13 food-spoilage and industrial yeast, including allspice, cinnamon, clove, garlic, onion, oregano, savory, and thyme.
Abstract: Thirty-two essential oils from plants were screened for inhibitory effects on 13 food-spoilage and industrial yeasts. Of these, essential oils of allspice, cinnamon, clove, garlic, onion, oregano, savory, and thyme were most inhibitory. Oils were subsequently tested for their effects on biomass production and pseudomycelium formation of eight genera of yeasts. Garlic oil was a potent inhibitor of yeast growth at concentrations as low as 25 ppm. The oils of onion, oregano and thyme were also strongly inhibitory. Essential oils (100 ppm) had no effect on pseudomycelium production by Candida lipolytica. However, all eight essential oils delayed pseudomycelium formation by Hansenula anomala, whereas six oils stimulated pseudomycelium production by Lodderomyces elongisporus. Cinnamon and clove oils were clearly stimulatory to pseudomycelium production by Saccharomyces cerevisiae.
386 citations
TL;DR: In this paper, the authors ranked common amino acids and amide derivatives according to the intensity of Maillard browning formed when heated in an autoclave at 121°C for 10 min, under identical conditions, with each of the sugars D-ribose, D-glucose,D-fructose, α-lactose and sucrose.
Abstract: Common amino acids and amide derivatives have been ranked according to the intensity of Maillard browning formed when heated in an autoclave at 121°C for 10 min, under identical conditions, with each of the sugars D-ribose, D-glucose, D-fructose, α-lactose and sucrose. The amino compounds have been grouped into high, intermediate and low browning producing groups. Browning formed by heating a representative of each group with D-glucose, D-fructose and α-lactose at pH values ranging from 6–12 was studied. Maximum browning was obtained at a pH value of about 10 in all of the amino acid-sugar solutions tested.
324 citations
TL;DR: In this article, the role of hydrophobic interaction between the ester methyl groups in the gelation of high methoxyl pectins was investigated by using temperature and different cosolutes.
Abstract: The role of hydrophobic interaction between the ester methyl groups in the gelation of high methoxyl pectins was investigated by using temperature and different cosolutes to modify hydrophobic interaction in a controlled manner. Both rupture strength and gel threshold were found to be partly proportional to the free energy of hydrophobic interaction between CH3-groups in model systems. The size of junction zones and the standard free energy of gelation were proportional to the square of the degree of methoxylation, i.e. to the probability of ester methyl groups being opposed in contiguous lengths of polymer. The contribution from hydrophobic interaction to the free energy of gelation was about half that from hydrogen bonds.
268 citations
TL;DR: In this paper, a model system based on the combination of raw, gelatinized and dextrinized starch was used to represent the physicochemical properties of the extrudates.
Abstract: Corn starch extruded at 32.9, 29.2, 24.5, 22.5, 15.9 and 14.2% moisture was analyzed for expansion ratio, enzyme susceptibility, water solubility index, water absorption index, degree of gelatinization, paste viscosity and heat of gelatinization. A model system based on the combination of raw, gelatinized and dextrinized starch was used to represent the physicochemical properties of the extrudates. Reducing extrusion moisture content resulted in a progressive change from gelatinized-like to dextrinized-like properties. Maximum gelatinization was observed at about 28-29% moisture. Below 20% moisture, dextrinization becomes predominant during high- shear cooking-extrusion. Scanning electron micrographs also validate the assumptions of the model.
259 citations
TL;DR: In this article, the authors examined the cell walls of strawberry (Fragaria × ananassa, Duch. Dover) receptacle tissue to determine if these wall polymers might be involved in softening of this fruit.
Abstract: Polyuronides and hemicelluloses derived from ethanol powders or cell walls of strawberry (Fragaria × ananassa, Duch. Dover) receptacle tissue were examined to determine if these wall polymers might be involved in the softening of this fruit. Throughout maturation and ripening, total polyuronides increased on a per fruit basis although as a percentage of ethanol powder they remained constant. Gel-filtration chromatography confirmed that polyuronide solubility was not correlated with extensive enzymic hydrolysis, an observation consistent with the fact that D-galacturonanase (polygalacturonase) activity was not detected in strawberry fruit. The sugar composition of alkali-soluble wall polymers showed little change throughout development. However, changes occurred in the molecular weights of these polymers during ripening.
217 citations
TL;DR: In this article, high performance liquid chromatography (HPLC) was used to determine (-)-epicatechin concentrations among freshly harvested beans of verified genetic origin, ranging from 21.89-43.27 mg/g of dry defatted samples.
Abstract: As determined by high performance liquid chromatography, (-)- epicatechin concentrations among freshly harvested beans of verified genetic origin ranged from 21.89–43.27 mg/g of dry defatted samples. Fermented beans showed much lower concentrations (2–10 mg). During fermentation, a trend towards decrease in (-)-epicatechin content was observed. Commercial beans from areas with reputations for shipping well-fermented products contained lower levels of (-)-epicatechin than beans from regions where fermentation is less extensive.
215 citations
TL;DR: The rate of wheat starch digestibility in the presence or absence of polyphenols (catechin or tannic acid) and/or phytic acid at concentrations found in legumes was determined in an in vitro dialysis system as discussed by the authors.
Abstract: The rate of wheat starch digestibility in the presence or absence of polyphenols (catechin or tannic acid) and/or phytic acid at concentrations found in legumes was determined in an in vitro dialysis system. Addition of tannic acid and phytic acid reduced the starch digestibility 13 and 60% respectively, at 5 hr. Combined tannic and phytic acid reduced the digestibility at a level (63%) which did not differ significantly from that with only phytic acid. Catechin had no significant effect on rate of starch digestibility.
212 citations
TL;DR: In this article, a water soluble, carbohydrate layer (hydroxypropyl methylcellulose) and various kinds of lipid layers were tested for resistance to water vapor permeability.
Abstract: Edible films composed of a water soluble, carbohydrate layer (hydroxypropyl methylcellulose) and various kinds of lipid layers were tested for resistance to water vapor permeability. Films were tested at 25°C and a relative humidity differential of 85%. Films containing solid lipids, such as beeswax, paraffin, hydrogenated palm oil or stearic acid yielded permeabilities of 0.2 g · mil · day−1· mmHg−1 or less which is a smaller value than that for low density polyethylene.
211 citations
TL;DR: The effects of phytic acid and its interactions with divalent cations (Ca++ and Mg++) on α-amylase activity were investigated in model systems and were found to be of noncompetative type.
Abstract: The effects of phytic acid and its interactions with divalent cations (Ca++ and Mg++) on α-amylase activity were investigated in model systems. Amylase activity was influenced by both preincubation time with phytate as well as phytate concentration. At 6-30 mM concentrations, Ca++ and Mg++ ions lowered the enzyme activity by 9-34% and 24-49%, respectively. When divalent cations were added simultaneously with phytate, a slight increase in enzyme activity with Ca++ and lowered enzyme activity with Mg++ were observed, as compared to when added independently. The enzyme activity was only moderately lowered when phytate was first preincubated with the divalent cations. Amylase inhibition by phytate was found to be of noncompetative type with an apparent inhibitor constant of 1.75 mM under the assay conditions.
207 citations
TL;DR: In this article, two groups of wine consumers described the flavor characteristics of six unlabeled white wines and attempted to match descriptions to wines in subsequent tastings, one group was experienced in describing wine flavor and another group had no experience.
Abstract: Two groups of wine consumers described the flavor characteristics of six unlabeled white wines and attempted to match descriptions to wines in subsequent tastings. One group was experienced in describing wine flavor and another group had no experience. Experienced subjects used more terms describing odor qualities and more terms with concrete (vs abstract) references. Most of the terms were used by only one person for a given wine. Experts matched descriptions to wines better than nonexperts (mean correct = 2.6 for experts vs 1.8 for nonexperts). Composite descriptions assembled from the nonexpert group were more often matched correctly than their individual descriptions. Experts’ errors when matching descriptions were related to discriminability.
200 citations
TL;DR: In this article, a bilayer film consisting of stearic and palmitic acids as one layer and hydroxypropyl methylcellulose as the other was prepared, and it was tested under a variety of conditions involving film composition, temperature and relative humidity.
Abstract: A bilayer film consisting of stearic and palmitic acids as one layer and hydroxypropyl methylcellulose as the other was prepared. The permeability of this film to water vapor was tested under a variety of conditions involving film composition, temperature and relative humidity. This film exhibited permeability values (g · mil w m−2· day−1· mm Hg−1) of 0.5 at 40°C 0.3 at 25°C 1.7 at 5°C, and 6.0 at −19°C. This film would be expected to perform well at relative humidities below 90% and temperatures within the range of 40°C to -19°C.
TL;DR: In this paper, a 19 mm diameter, single screw extruder was used to study the physical and structural modifications that occur during extrusion cooking of wheat starch, and structural modification of the starch polymers was investigated using gel permeation chromatography (GPC), enzymatic digestions and dilute solution viscometry.
Abstract: Wheat starch was processed in a 19 mm diameter, single screw extruder to study the physical and structural modifications that occur during extrusion cooking. Structural modification of the starch polymers was investigated using gel permeation chromatography (GPC), enzymatic digestions and dilute solution viscometry. Both the GPC and intrinsic viscosity results showed that the average molecular size significantly decreased as a result of extrusion processing. The relative amount of material excluded by Bio-Gel A150m was considerably lower for extruded samples than for unprocessed wheat starch and this size reduction of the amylopectin fraction was attributed to mechanical rupture of covalent bonds. The characterization of the structural modifications of the starch polymers is reported.
TL;DR: In this article, the effect of combinations of phosphate type [tetrasodium pyrophosphate (PP), sodium tripolyphosphate(TPP), sodium tetrapolyph phosphate (TTPP), and sodium-hexametaphosphates(HMP)], phosohate concentration (0.125-0.500%), and salt level (0 6-2.0%) on the binding in restructured beef rolls was studied.
Abstract: The effect of combinations of phosphate type [tetrasodium pyrophosphate (PP), sodium tripolyphosphate (TPP), sodium tetrapolyphosphate (TTPP), and sodium-hexametaphosphate(HMP)], phosohate concentration (0.125%-0.500%). and salt level (0.6%-2.0%) on the binding in restructured beef rolls was studied. The rolls were prepared either with or without a homogenate that contained all the added salts. Preparation method had little effect on binding. The effectiveness of the phosphates was: PP > TPP > TTPP > HMP. Changes in binding produced by varying phosphate type, phosphate concentration and salt level could be explained in terms of changes in ionic strength and pH. Between 90% and 96% of the variation in binding could be explained in terms of these two variables.
TL;DR: In this article, the sensory interactions of monosodium glutamate (MSG) and NaCl in a clear soup were examined by a sensory test, by a response-surface method.
Abstract: The sensory interactions of monosodium glutamate (MSG) and NaCl in a clear soup were examined by a sensory test, by a response-surface method The extents of saltiness and palatability were expressed by second order polynomials of the concentrations of MSG and NaCl added The polynomials indicated that to provide an appropriate saltiness and the maximum palatability score, more NaCl was required in soup with a lower MSG concentration, and vice versa It is recommended that when the amount of sodium in the soup must be restricted while retaining a high palatability score, the NaCl level should be reduced while adding an optimal MSG level
TL;DR: In this article, the use of unsaturated NaCl solutions as isopiestic standards for calibration of hygrometers is proposed, and it is shown that there is an excellent agreement on the exact value of NaCl solution between various literature compilations and theoretical models.
Abstract: In view of the uncertainty aboui the exact water activity.(aw) of some solutions (saturated and unsaturated) used as references sources, the use of unsaturated NaCl solutions as isopiestic standards for calibration of hygrometers is proposed. It is shown that there is an excellent agreement on the exact value of NaCl solutions between various literature compilations and theoretical models. Further, it is also shown that in the important range (for food related applications) of 15–50°C the aw of NaCl solutions is almost invariant.
TL;DR: In this article, a continuous evaluation of changes in structural rigidity and energy damping during heating of the sols from 3° to 95°C was performed in a nondestructive, temperature-controlled Thermal Scanning Rigidity Monitor.
Abstract: Sols were prepared from comminuted fish (surimi), beef, pork and turkey muscles. Continuous evaluation of changes in structural rigidity and energy damping during heating of the sols from 3° to 95°C was performed in a nondestructive, temperature-controlled Thermal Scanning Rigidity Monitor. Surimi presented major rigidity transitions at 40°. 48° and 65°C; beef at 43°. 56° and 69°C; pork at 44°, 53° and 69°C; and turkey at 50°, 53° and 79°C. All materials exhibited rapid decrease in energy damping (i.e. increase in elasticity) over a short temperature span. Failure testing of gels indicated differences in strength and deformability. SEM micrographs provided an insight into structural features of the gels.
TL;DR: The chemical composition and nutritional quality of camel milk was studied in this article, which showed 11.7% total solids, 3.0% protein and 3.6% fat, 0.8% ash, 4.4% lactose and 0.13% acidity.
Abstract: The chemical composition and nutritional quality of camel milk was studied. Results showed 11.7% total solids, 3.0% protein, 3.6% fat, 0.8% ash, 4.4% lactose, 0.13% acidity and a pH of 6.5. The levels of Na, K, Zn, Fe, Cu, Mn, niacin and vitamin C were higher and thiamin, riboflavin, folacin, vitamin Bt12, pantothenic acid, vitamin A, lysine and tryptophan were relatively lower than those of cow milk. Gas liquid chromatography analysis of milk fat showed a molar percent of 26.7 for palmitic, 25.5 oleic, 11.4 myristic, and 11.0 palmitoleic. In vitro protein digestibility and calculated protein efficiency ratio values were 81.4% and 2.69, respectively, based on 90.0% and 2.50 for ANRC-Casein.
TL;DR: Sensitivity of strains of S. aureus, B. cereus, Pseudomonas sp., and S. typhimurium to sage was studied in nutrient broth and in foods as discussed by the authors.
Abstract: Sensitivity of strains of S. aureus, B. cereus, Pseudomonas sp. and S. typhimurium to sage was studied in nutrient broth and in foods. Inhibition was highest in broth (MIC of 0.0–1.0%), and diminished in rice (MIC of 0.4 to >2.5%), and chicken and noodles (MIC of 1.0 to >2.5%). Little or no inhibition was seen in meat at ≤2.5% of sage. In each growth medium B. cereus strains displayed the least resistance, followed by S. aureus, Pseudomonas sp., and S. typhimurium. Growth from spores of B. cereus was inhibited in a manner similar to that seen in vegetative cells. While antimicrobial activity of sage increased with increase in the volatile oil fraction, essential oils alone had limited inhibitory effect in broth, and no effect in foods. Salt and water levels in the food increased bacterial sensitivity, whereas fat and protein decreased it.
TL;DR: In this article, surface hydrophobicity (So) of crude salt extracts of meat was determined fluorometrically using cis-parinaric acid as a probe, and backward stepwise multiple regression equations for prediction of emulsifying activity index (EAI) and emulsification capacity (EC) were presented.
Abstract: Surface hydrophobicity (So) of crude salt extracts of meat was determined fluorometrically using cis-parinaric acid as a probe. Upon heating the extracts to 70°C, So increased two- to threefold, whereas protein solubility (s) decreased to 20%. Further heating (to 85°C) resulted in slight decreases in both So and s. Backwards stepwise multiple regression equations for prediction of emulsifying activity index (EAI) and emulsifying capacity (EC) were: EAI = 2.658 + 0.0001308 sSo, and EC =−35.30 + 6.459 s + 0.001317 sSo− 0.05463 s2. So was most important for predicting emulsifying properties of samples with high (>50%) solubility, whereas solubility parameters were more influential for samples with low (<50%) solubility.
TL;DR: In this paper, three 65° Brix low-pulp concentrated orange juice (COJ) samples, between −19 and 30°C were shear-thinning (pseudoplastic) fluids with negligible magnitudes of yield stress.
Abstract: Three 65° Brix low-pulp concentrated orange juice (COJ) samples, between −19 and 30°C were shear-thinning (pseudoplastic) fluids with negligible magnitudes of yield stress. The simple power law model fit welt the shear rate-shear stress data. For one sample, the Powell-Eyring model also described the data well. The Arrhenius model described the effect of temperature on the apparent viscosity and the consistency index of the power law model. The activation energy of flow (Ea) was 10.7 ± 0.2 kcal/g mole. The models of Harper and El Sahrigi and Christiansen and Craig were suitable for describing the combined effect of temperature and shear rate. The magnitude of Ea decreased with decrease in concentration. Apparent viscosity and K increased exponeitially with concentration.
TL;DR: The covalent linkage of nonmeat proteins to myosin at temperatures and pH's common in meat product processing was investigated and casein was the best substrate.
Abstract: The covalent linkage of nonmeat proteins to myosin at temperatures and pH's common in meat product processing was investigated. Iodinated proteins were cross-linked to immobilized myosin and then quantitated by gamma counting after noncross-linked material was removed by washing with 6M guanidine hydrochloride. Bovine plasma transglutaminase catalyzed the formation of e- (γ-glutamyl) lysine cross-links between myosin and soya protein, casein or gluten at 4-5°C for 16 hr and at pH's from 5.5-7.0. Casein was the best substrate with approximately 0.4g of casein cross-linked to 1.0g myosin.
TL;DR: In this article, three different methods for determining nonheme iron content of meat extracts which differed in final pH and either in heating or not heating of the samples, were compared.
Abstract: Three different methods for determining nonheme iron content of meat extracts which differed in final pH and either in heating or not heating of the samples, were compared. The final pH of meat extracts had little effect on the level of nonheme iron but heating gave higher values. Both final temperature and rate of heating influenced release of nonheme iron from meat pigment extracts, with the optimum temperature being 63-70°C. Slow heating resulted in release of more noneheme iron than fast heating. Nitrite was shown to prevent release of heme iron, apparently through stabilizing the porphyrin ring. Sources of nonheme iron and their relationship to oxidation in cooked meat are discussed.
TL;DR: In this paper, the authors investigated the rate of browning in Red Delicious and Granny Smith apple juice concentrates during storage and found that browning occurred at a faster rate in red Delicious.
Abstract: Rate of browning in Red Delicious and Granny Smith apple juice concentrates during storage was investigated. Color development at 65°, 70° and 75°Brix and storage temperatures of 5°, 20° and 37°C were compared over 120 days. Color deterioration occured at a faster rate in Red Delicious. Reaction at different concentration and storage conditions was exponential, following an Arrhenius-type dependence with temperature. Activation energy for a solids content of 65 - 75°Brix ranged from 16.4 - 19.3 Kcal/mole. Influence of juice variety on activation energy was negligible. Water activity results are in general agreement with those reported by other investigators. A satisfactory correlation to predict commercial concentrate browning has been obtained. All other things being equal, thermal history is a critical factor to obtain a lighter color concentrate.
TL;DR: In this paper, two traditional cheese meltability tests, the Schreiber and Arnott, as well as two microwave modifications thereof were compared on a variety of mild and sharp cheddar, process American, and mozzarella cheeses and various process cheese products.
Abstract: Two traditional cheese meltability tests, the Schreiber and Arnott, as well as two microwave modifications thereof were compared on a variety of mild and sharp cheddar, process American, and mozzarella cheeses and various process cheese products. There was a marked lack of correlation between the Schreiber and Arnott results indicating that at least two material properties control meltability. The effects of variations in heating time and oven temperature in the nonmicrowave tests and heating time in the microwave tests were determined. Differential scanning calorimetry did not reveal differences useful in predicting melting behavior.
TL;DR: In this article, the effect of high temperature, high humidity storage on cooking quality and physicochemical properties of dry, mature red kidney beans was evaluated over a storage period of 9 months.
Abstract: The effect of high temperature, high humidity storage on cooking quality and physicochemical properties of dry, mature red kidney beans was evaluated over a storage period of 9 months. The rate of softening of beans during cooking, and the rate of dissolution of pectin during cooking followed apparent first-order kinetics and their apparent rate constants correlated highly with each other. The apparent softening rate constants decreased with increasing time of storage. The loss of cookability in mature bean seeds stored under high temperature-high humidity conditions probably results from a decrease in phytic acid phosphorus and alterations in the ratio of monovalent to divalent cations in the tissue.
TL;DR: In this paper, the Baumann capillary suction apparatus, the AACC standard centrifugation method, moisture sorption isotherm values and freezing point by cryoscopic osmometry were used to measure the water binding capacity (WBC) of several fiber sources.
Abstract: The Baumann capillary suction apparatus, the AACC standard centrifugation method, moisture sorption isotherm values and freezing point by cryoscopic osmometry were used to measure the water binding capacity (WBC) of several fiber sources. Although each method was able to distinguish between ingredients of different WBC's, the values obtained by the four methods were very different from each other. A significant correlation was only found between the Baumann data and the moisture sorption data for fruit, cereal and legume fibers, while no method correlated with the WBC as determined by the cryoscopic method. This suggests that the different methods evaluate different mechanisms of water binding and that one must carefully choose the proper method in predicting the water binding functionality of fibers in foods.
TL;DR: In this paper, the effects of fat level (14, 19, 24%) and cooking method (electric broiling, charbroiling, conventional oven roasting, convection oven Roasting, electric grill frying, microwave cooking) were evaluated with ground beef patties using descriptive attribute and texture profile panels.
Abstract: Effects of fat level (14, 19, 24%) and cooking method (electric broiling, charbroiling, conventional oven roasting, convection oven roasting, electric grill frying, microwave cooking) were evaluated with ground beef patties using descriptive attribute and texture profile panels. Higher tenderness and juiciness values were associated with higher fat levels in the patties. Texture profile evaluation indicated the higher tenderness associated with higher fat levels and conventional oven roasting to be due to less hardness, density and cohesiveness during initial biting of the sample. Microwave cooking produced low sensory panel ratings regardless of fat level, while patties cooked by frying had the highest ground beef flavor intensity scores. Major textural properties of cohesiveness, hardness and density were influenced by fat level in a similar manner for all cooking methods.
TL;DR: In this article, the effect of extrusion cooking in a single screw extruder on the molecular weight distribution of wheat starch was correlated to the starch melt rheology, and a simple first-order model was developed which defined the extent of mechanical degradation of the amylopectin component as a function of nominal shear stress and residence time in the extruder.
Abstract: The effect of extrusion cooking in a single screw extruder on the molecular weight distribution of wheat starch was correlated to the starch melt rheology. A simple first-order model has been developed which defines the extent of mechanical degradation of the amylopectin component as a function of nominal shear stress and residence time in the extruder. A limited set of experimental observations were used to test the model. Iso-shear stress curves were calculated for the experimental range of conditions. The curves can be used, in conjunction with estimates of the residence time, to calculate equivalent processing conditions, and to predict the extent of amylopectin degradation. The model may allow the use of small extruders to determine fundamental process parameters for full scale extrusion.
TL;DR: A systematic procedure for testing the accuracy of freezing time prediction methods involves carrying out predictions by an accurate numerical method as well as the method under test, and careful cross-checking of prediction errors for correlation with a number of physical parameters.
Abstract: A systematic procedure for testing the accuracy of freezing time prediction methods is discussed. It involves carrying out freezing time predictions by an accurate numerical method as well as the method under test, and careful cross-checking of prediction errors for correlation with a number of physical parameters. Criteria are given for selection of an appropriate numerical method. The need for systematic cross-checking is illustrated by comparisons between four recent prediction methods. The comparisons show the strengths and weaknesses of the four methods. They also indicate general shortcomings in available methods and data, and so highlight those areas in which future research might be most profitable.
TL;DR: In this article, dry-milled corn germ was extracted with supercritical carbon dioxide (SC-CO2) at 5,000-8,000 psi and 50°C.
Abstract: Dry-milled corn germ was extracted with supercritical carbon dioxide (SC-CO2) at 5,000-8,000 psi and 50°C. CO2-extracted oil was lower in free fatty acids and refining loss, and was lighter in color when compared with a commercial expeller-milled crude oil. Total unsaponifiable and tocopherol contents were similar for both oil types. The defatted, highly friable flour has a shelf-stable moisture content of 2-3% and good flavor quality. The flour contains 20% protein with good amino acid balance, meeting FAO specifications for food protein supplements. High pressure SC-CO2 extraction also denatures the proteins, including oxidative enzymes. Peroxidase activity is reduced tenfold in SC-CO2-extracted flour when compared with hexane-extracted flours. Storage tests for 5 wk at 38°C and for 2 months at 25°C show that flavor quality of untoasted SC-CO2-defatted germ flour is maintained even under these extreme conditions.