Showing papers in "Journal of Food Science in 1981"
TL;DR: In this paper, the properties of the Great Northern bean (Phaseolus vulgaris L.) flour, albumins, globulins, protein concentrates, and protein isolates were investigated.
Abstract: Functional properties of the Great Northern bean (Phaseolus vulgaris L.) flour, albumins, globulins, protein concentrates, and protein isolates were investigated. Protein concentrates had the highest water and oil absorption capacity (5.93 and 4.12 g/g, respectively) among all the samples studied. Protein concentrates registered the highest emulsion capacity (72.6g oil emulsified/g) while albumins had the highest emulsion stability (less than 5 ml separation of phase in 780 hr at room temperature of 21°C). Foaming ability of the Great Northern bean proteins was fair. Foamability of the proteins was concentration dependent.
457 citations
TL;DR: In this article, potato chips, popcorn, puffed corn curls, and saltines were equilibrated to various water activities (aw) over saturated salt solutions, and sensory panels determined the crispness and textural hedonic quality of the humidified products by the magnitude estimation technique coupled to a verbal concept scale.
Abstract: Potato chips, popcorn, puffed corn curls, and saltines were equilibrated to various water activities (aw) over saturated salt solutions. Sensory panels determined the crispness and textural hedonic quality of the humidified products by the magnitude estimation technique coupled to a verbal concept scale. Critical water activities (ac), where the products became organoleptically unacceptable, generally fell in the 0.35–0.50 aw range. Instron analyses showed that the force-deformation curve changed distinctly near the ac for saltines and puffed corn curls, while the curve changed more gradually with increasing aw for popcorn. Potato chips did not produce a consistently shaped force-deformation curve. The cohesiveness value of popcorn was found to be a good indicator of its sensory crispness.
357 citations
TL;DR: The chemical composition of 10 amaranth seed samples was determined using gas chromatography and high performance liquid chromatography as discussed by the authors, and the amino acid composition of the grain was used to calculate the chemical score (73) and the nitrogen to protein conversion factor (5.85).
Abstract: The chemical composition of ten amaranth seed samples was determined. The saccharide content was determined using gas chromatography and high performance liquid chromatography. Sucrose was the major sugar followed by raffinose. Inositol, stachyose, and maltose were found in small amounts in most of the samples. Autolysis for 16 hr at pH 5.0 and 6.5 resulted in decreased sucrose and raffinose concentrations. Maltose was liberated by autolysis at pH 6.5 but not at pH 5.0. Inositol increased after autolysis. It was concluded that invertase, amylase, and phytase occur in the grain. Physicochemical properties of isolated amaranthus starch were measured and compared with analogous values reported for wheat starch. The lipids from representative amaranth grain varieties were analyzed for fatty acid composition. Squalene was present in the oil in large amounts, compared to other grains. The amino acid composition of the grain was used to calculate the chemical score (73) and the nitrogen to protein conversion factor (5.85). Leucine was found to be the limiting amino acid. Tannin and vitamin levels typical of other grains were detected. Mineral and proximate compositions were similar to previously reported values.
293 citations
TL;DR: Two features of the heat-induced gelation of myosin, aggregation and three-dimensional network formation were found to be imparted by the subfragment 1 and the rod, respectively.
Abstract: Myosin molecules are cleaved by chymotrypsin digestion into two fragments: subfragment 1, which originates from the globular heads of myosin, and the myosin rod, which originates from the helical tail of the myosin molecule. The heat-induced gelation of these subfragments was compared to that of intact myosin by measuring rigidity, turbidity, and other physico-chemical characteristics of each system. Two features of the heat-induced gelation of myosin, aggregation and three-dimensional network formation were found to be imparted by the subfragment 1 and the rod, respectively. The former involves disulfide exchange and the latter relates to conformational changes arising from a partially irreversible helix-coil transition during heating. Possible relationships are suggested between these physicochemical changes of the myosin head and tail regions upon heating and the heat-induced gelation of myosin.
255 citations
TL;DR: A procedure for isolating and purifying polyphenoloxidase from banana pulp is described, which revealed the presence of a fluorescent compound with Rf= 0.57, which was identical with chlorogenic acid.
Abstract: A procedure for isolating and purifying polyphenoloxidase from banana pulp is described. Maximum activity was obtained from the inner portion of the pulp by extraction with 0.2M sodium phosphate buffer, pH 7.0, containing 1% insoluble PVP and 0.25% Triton X-100. The enzyme was purified 38.8-fold after acetone precipitation, re-extraction of the precipitate with phosphate buffer containing Triton X-100, storage in the freezer for 7 days (-40°C), chromatography on Sephadex G-100 and electrophoresis on polyacrylamide gel. The purified enzyme (four isozymes) gave a poly-peptide molecular weight (SDS-gel) of 31,000 ± 1,000 and molecular weight on sucrose gradient ultracentrifugation of 62,000 ± 2,000. The isoelectric point, determined by isoelectric focusing on polyacrylamide gel, was 5.2. The enzyme was stable at 55°C for 30 min; it lost mole than 90% of the activity after 5 min at 85°C and was completely inactivated at 95°C for the same time. The absorption spectrum of the purified enzyme showed a maximum at 278 nm and a shoulder at 340-350 nm. This preparation, when submitted to paper chromatography revealed the presence of a fluorescent compound with Rf= 0.57, which was identical with chlorogenic acid.
240 citations
TL;DR: In this paper, an improved method of measuring expressible moisture is described which is simple and reproducible, it basically measures the amount of liquid squeezed out of a protein system with centrifugal force, by measuring the weight gain of a filter paper surrounding the sample.
Abstract: With the development of more refined methods of measuring water-binding properties of meats, the term “water-holding capacity” needs to be replaced with more specific and carefully defined terms such as expressible moisture, water-binding potential, and free drip. An improved method of measuring expressible moisture is described which is simple and reproducible. It basically measures the amount of liquid squeezed out of a protein system with centrifugal force, by measuring the weight gain of a filter paper surrounding the sample. This method seems to be highly sensitive to factors that affect the water-binding properties of muscle foods.
236 citations
TL;DR: In this article, a simple isocratic HPLC technique was developed for the quantitative analysis of organic acids in dairy products using an Ammex HPX-87 column at 65°C, 0.0090N H2SO4 mobile phase and UV detection at 220 and 275 nm.
Abstract: A simple isocratic HPLC technique was developed for the quantitative analysis of organic acids in dairy products. An Ammex HPX- 87 column at 65°C, 0.0090N H2SO4 mobile phase and UV detection at 220 and 275 nm were utilized. Orotic, citric, pyruvic, lactic, uric, formic, acetic, propionic, butyric, and hippuric acids were quantitated for whole milk, skim powder, cultured buttermilk, sour cream, cottage cheese, yogurt, sharp Cheddar cheese, and blue cheese. Over 90% recoveries of acids added to whole milk were observed for ail acids except butyrid; the average recovery for butyric was 86%.
213 citations
TL;DR: The levels of trypsin inhibitors activity were higher in both kabuli and desi seeds of chickpea than their chymotrypsin inhibitor activity and polyphenolic compounds exhibited a highly significant and negative corretation with in vitro digestibility of protein.
Abstract: The levels of trypsin inhibitor activity were higher in both kabuli and desi seeds of chickpea than their chymotrypsin inhibitor activity. Mean values for the trypsin and chymotrypsin inhibitor units in dhal and seed samples of desi were higher as compared with kabuli cultivars. The presence of seed coat reduced the protein extraction. Mean values of polyphenolic compounds in seed samples of desi were more than twice that of kabuli and these differences disappeared in dhal samples indicating the distribution of these compounds mainly in the seed coat. The in vitro protein digestibility studies showed larger differences between desi seed and dhal samples when compared with kabuli seed and dhal samples. Polyphenolic compounds exhibited a highly significant and negative corretation (r = 0.872**) with in vitro digestibility of protein and a significant positive correlation with trypsin (r = 0.612*) and chymotrypsin (r = 0.507*) inhibitor activities.
191 citations
TL;DR: In this paper, a red bean (Phaseolus radiatus var. aurea) starch was isolated by a wet-milling process and steeping in 0.1% sodium hydroxide which gave the best starch purity.
Abstract: Red bean (Phaseolus radiatus var. aurea) starch was isolated by a wet-milling process and steeping in 0.1% sodium hydroxide which gave the best starch purity. Physical properties of the starch including granule sizes, gelatinization temperature range, iodine affinity, X-ray diffractogram, swelling and solubility pattern, Brabender amylogram, gel strength and degree of syneresis, were examined. Starch noodles were prepared from red bean starch and compared with those from mung bean. Noodle quality was exmained by solid loss during cooking, tensile strength and organoleptic tests. The results indicated that red bean starch noodles gave fairly good quality, although not as good as mung bean starch noodles.
164 citations
TL;DR: The yield of the Great Northern bean starch was 18.23% (bean flour basis) and the starch granule size ranged from 12 × 12 μm to 58 × 40 μm (length × width).
Abstract: The yield of the Great Northern bean starch was 18.23% (bean flour basis). The starch granule size ranged from 12 × 12 μm to 58 × 40 μm (length × width). The shape of starch granules was round to oval to elliptical, and in some cases, concave as well. Lamellae were present on all the starch granules observed. Amylose content of the starch was 10.2% (starch basis). Hog pancreatic α-amylase hydrolyzed more starch than did malt α-amylase under similar conditions. The Great Northern bean starch had good water and oil absorption capacities at room temperature (21°C). The bean starch formed a stable gel at concentrations of 7% and above (w/v). The viscoamylographic studies of the isolated starch indicated the restricted-swelling character of the bean starch.
163 citations
TL;DR: In this paper, a synthetic extract, prepared from 44 pure chemicals on the basis of the analytical data on the leg meat extract of the boiled snow crab, Chionoecetes opilio, satisfactorily reproduced the taste of the natural extract except for a slight lack of body and mildness.
Abstract: A synthetic extract, prepared from 44 pure chemicals on the basis of the analytical data on the leg meat extract of the boiled snow crab, Chionoecetes opilio, satisfactorily reproduced the taste of the natural extract except for a slight lack of body and mildness. A series of taste panel assessments on synthetic extracts prepared by omitting or adding extractive component(s) were carried out by a triangle difference test and changes in taste profile were assessed. Only 12 components, Ala, Arg, Glu, Gly, glycine betaine, AMP, CMP, GMP, Na+, K+, Cl−, and PO43-, were found to contribute more or less toward producing the characteristic taste of the snow crab.
TL;DR: In this paper, a high-performance liquid chromatographic (HPLC) method has been developed to determine fructose, glucose, and sucrose content of potatoes, which was complete in 30 min.
Abstract: A high-performance liquid chromatographic (HPLC) method has been developed to determine fructose, glucose, and sucrose content of potatoes. The HPLC system consisted of a μBondapak/ carbohydrate column, a solvent system of acetonitrile-water (75: 25), a flowrate of 1.8 ml/min, and a refractive index detector. Analysis, including sample preparation, was complete in 30 min. With the exception of high concentrations of sucrose (8 mg/g or above), the method recovered 93% or more of all sugars. The coefficients of variation for the procedure ranged from 1.39-13.31%. TLC indicated that there were no interfering compounds eluting with any of the three sugars.
TL;DR: The navy bean, red kidney bean and wrinkled-seeded field pea induced the highest levels of hydrogen to be produced by the laboratory rat, and significant, positive correlations were determined between hydrogen production and the following chemical components: stachyose, raffinose plus stachyOSE, and glucans and pentosans hydrolyzable in dilute acid.
Abstract: The objective of this study was to investigate the relationship between flatulence potencial and carbohydrate composition of legume seeds. The navy bean, red kidney bean and wrinkled-seeded field pea induced the highest levels of hydrogen to be produced by the laboratory rat. The garbanzo bean and smooth-seeded field pea gave intermediate values whereas the mung bean and green lentil showed values which were not significantly different from the control, non-flatulent diet. Significant, positive correlations were determined between hydrogen production and the following chemical components: stachyose, raffinose plus stachyose, and glucans and pentosans hydrolyzable in dilute acid. Significant, negative correlations were determined between hydrogen production and starch or lignin contents.
TL;DR: In this paper, the authors found that the higher the moisture content after soaking, the shorter the cooking time, and that the cotyledon deteriorated during aging, indicating that the water absorption rate was greater from stored beans than from fresh samples.
Abstract: Black beans stored for 7–14 days at 41°C, 100% RH, required more cooking time than fresh beans and thus paralleled cooking time for beans stored forr more than 1 yr at room temperature. With corrections for solids lost during soaking, water absorption did not differ between fresh and stored beans. The rate of electrolyte leakage was greater from stored beans than from fresh samples, indicating that the cotyledon deteriorated during aging. Bean moisture content was found to be related to cooking time. In general, the higher the moisture content after soaking, the shorter the cooking time. However differences in cooking times between fresh and aged samples persisted regardless of bean moisture content.
TL;DR: Ascorbic acid had a statistically significant effect on all parameters, including anthocyanin loss under both oxygen and nitrogen environments, catechin loss, increase in browning and polymeric color, decrease in Hunter “a” value and increase in Hunter L value as discussed by the authors.
Abstract: Interactions between ascorbic acid, pelargonidin-3-glucoside, and catechin were studied in pH 3.4 citrate-phosphate buffer at 20°C under anaerobic and oxygenated conditions. Changes in anthocyanin pigment, ascorbic acid, dehydroascorbic acid, and catechin were quantitatively measured during 130 days storage along with Hunter color parameters, browning, and polymeric color. Ascorbic acid had a statistically significant effect on all parameters, including anthocyanin loss under both oxygen and nitrogen environments, catechin loss, increase in browning and polymeric color, decrease in Hunter “a” value and increase in Hunter L value. Ascorbic acid bleached anthocyanin pigment and also induced browning. There is evidence that anthocyanin pigment and ascorbic acid degrade through a direct condensation mechanism.
TL;DR: In this article, a pea protein isolate from field peas was obtained by alkaline extraction and precipitation at the isoelectric point, and drying was carried out by freeze, spray and drum processes.
Abstract: Laboratory and pilot plant processes were developed for producing pea protein isolate from field peas. Sodium proteinate and isoelectric products containing up to 90% protein were obtained by alkaline extraction and precipitation at the isoelectric point. Drying was carried out by freeze, spray and drum processes. Chemical analysis, functional properties, color and flavor of the dried isolates compared favorably with their soy counterparts. Generally, the sodium proteinates exhibited more functionality than isoelectric isolates. Drum drying decreased the nitrogen solubility index and increased water absorption. Freeze- and spray-drying resulted in isolates with the highest emulsification and water absorption values. Spray drying produced the best foaming, color and flavor properties.
TL;DR: Although the fermentation produced increased availability of nutrients, it did not produce change in the proximate analyses and protein and carbohydrate appeared to be more available after the fermentation than before the fermentation.
Abstract: A natural lactic fermentation of ground grain sorghum produced significant increases (P < 0.001) in available lysine/leucine, isoleucine, and methionine. The protein quality, expressed as relative nutritive value, increased significantly (P < 0.001) as a result of fermentation. Niacin and thiamin increased significantly (P < 0.001) and riboflavin also increased (P < 0.05) during the fermentation. Protein and carbohydrate appeared to be more available after the fermentation than before the fermentation. Although the fermentation produced increased availability of nutrients, it did not produce change in the proximate analyses.
TL;DR: The relationship of the distribution of pectic substances to tissue softening was examined in ripening mangos at four stages of ripeness in this paper, showing that polygalacturonase and cellulase activity of cell wall preparations from ripe mangos increased during 4°C storage.
Abstract: The relationship of the distribution of pectic substances to tissue softening was examined in ripening mangos at four stages of ripeness. Water-soluble and alkali-soluble pectin declined and ammonium oxalate soluble pectin increased as the mango lost its firmness and became soft. Polygalacturonase and cellulase activities of cell wall preparations increased markedly during ripening. The decline in alkali-soluble pectin and the increase in polygalacturonase activity correlated well with the loss of firmness. Alkali-soluble pectin declined slowly in ripe mangos stored at 4°C. This decline correlated with loss of firmness of the stored mangos. The cellulase activity of cell wall preparations from ripe mangos increased during 4°C storage and the increase correlated with the decrease in firmness.
TL;DR: The characteristics of spaghetti produced from two high temperature (HT) drying cycles, one featuring HT at the initial stages of drying (HT-A) and another featuring HT during the latter stages of the drying process as discussed by the authors, were compared to spaghetti produced by low temperature (LT) drying.
Abstract: The characteristics of spaghetti produced from two high temperature (HT) drying cycles, one featuring HT at the initial stages of drying (HT-A) and one featuring HT during the latter stages of drying (HT-B) were compared to spaghetti produced by low temperature (LT) drying. Both HT cycles had the advantage of greatly reduced drying time. In addition HT-A spaghetti exhibited much enhanced color intensity compared to LT spaghetti. Although HT-A spaghetti cooking properties were marginally inferior to LT spaghetti, cooking quality was still satisfactory. Spaghetti from HT-B was equal to or better than LT spaghetti in color quality while also exhibiting improved strand strength and superior cooking properties.
TL;DR: For instance, this paper found that the perceived crispness and loudness of chewing sounds were correlated both when food samples were fractured by single bites and when further broken down by chewing.
Abstract: ABSTRACT The relationships lretween biting and chewing sounds and judgments of food crispness vfere examined in two studies. In the fist, subjects used magnitude es1 imation to separately judge the loudness of chew- ing sounds and the crispness of a wide range of wet and dry crisp foods. Judgments of perceived crispness and loudness were highly correlated both when food samples were fractured by single bites and when further broken down by chewing. In the second study, biting and chewing sounds were blocked by a loud masking noise. Subjects had no difficulty determining crispness. Correlations between judgments obtained with and without an auditory block were high. It is lroposed that vibrations produced by fracturing crisp foods may ur deriie the perception of crispness. THE ROLE of sound in judgments of food quality was first examined Iry Drake (1963) who showed that sounds produced by crtrshing a variety of foods differed in ampli- tude, frequency, and temporal characteristics. The author suggested that 4:hewing sounds and related vibrations are utilized as a complement to other tactile cues in the sensory evaluation of tire mechanical properties of foods. Drake (1965) also formd a significant correlation between the measured ampli:ude of chewing sounds and sensory deter- minations of their loudness for a variety of crisp foods. Vickers and Bourne (1976) suggested that acoustical sensations are involved in the perception of crispness in foods. They found that crisp foods, when bitten, produced a characteristic .rcoustical profile and hypothesized that the amplitude of the: sounds produced by biting a food was the most salient dinlension of crispness. Sherman and Deghaidy (1978) reportec. that their panelists used auditory cues, particularly dur.ng the first bite, to determine food crisp- ness. Vickers and Wasserman (1980) demonstrated that subjects could successfully rate the sensation of crispness by listening to tape-recorded sounds of the foods being crushed. Furthe::more, there was a high positive correlation between the per:eived loudness of the food crushing sounds and their perceij ed crispness. The cumulative data strongly suggest that biting and chewing sounds particularly the loudness of these sounds, correlate with tlte sensation of crispness in foods. This hy- pothesis was te:.ted in the first experiment. Subjects were instructed to either bite or bite and chew a series of foods varying in crisp less. Using magnitude estimation, the sub- jects separately evaluated the loudness of their chewing sounds and the crispness of the food samples; correlations were obtained bt:tween the two sets of judgments. A second exIreriment tested the more general hypothesis that auditory sensations are necessary for judgments of crispness. Subjec:ts judged the crispness of a series of foods while their bitirlg and chewing sounds were blocked by a
Abstract: Alkali and heat induce changes in proteins. These include racemization of L- to D-amino acids and crosslinking via lysinoalanine. Since high-quality proteins are presumably well-digested, possible effects of D-amino acid and lysinoalanine contents on food casein digestibility was examined. The following variables, which were expected to influence all three parameters, were evaluated: (a) pH (8-14); (b) temperature (25-75°C); and (c) time of treatment (10 min to 24 hr). An approximately inverse relationship was observed between D-ammo acid and lysinoalanine content and the extent of proteolysis. Such changes may lower the quality and safety of foods.
TL;DR: In this article, the number, percent, area and mean diameter of β-red (βR), α-white (αW) and α-red(αR) muscle fibers were determined.
Abstract: Beef carcasses (n = 65) were selected to range widely in marbling (moderately abundan: to practically devoid) and maturity (A, n = 25; B, n = 19; C, n = 6; D, n = 8; E, n = 7). Number, percent, area and mean diameter of β-red (βR), α-white (αW) and α-red (αR) muscle fibers were determined. Warner-Bratzler shear force values and taste panel tenderness ratings were also obtained. αW muscle fiber parameters were negatively correlated (P < 0.05) to marbling and tenderness ratings while αR and βR parameters were positively correlated (P < 0.05) to these quality attributes. The ratio of αW fiber area to βR and/or αR fiber area was correlated (P < 0.05) with marbling and tenderness. Regression analyses indicate that muscle fiber type composition is more highly related to marbling (marb) than it is to shear force value (SFV) or tenderness rating (TR) although all relationships were significant (P < 0.10). The relationship of these quality indicators to fiber type is greater within A maturity [marb, coefficient of determination (C.D.) = 65.09; SFV, C.D. = 65.09; SFV, C.D. = 28.85; TR, C.D. = 62.94] than for the entire population (murb, C.D. = 49.16; SFV, C.D. = 18.71; TR, C.D. = 30.47). It appears that the oxidative capacity of a muscle is related to marbling and tenderness and that muscle fiber type composition could possibly be used as a predictor of marbling potential.
TL;DR: Nisin, an antibiotic produced by certain strains of Streptococcus lactis, is effective in preventing the outgrowth of Clostridium botulinum spores and the need for higher levels of nisin in cooked medium to prevent spore outgrowth is due to the binding of the nisin by meat particles.
Abstract: Nisin, an antibiotic produced by certain strains of Streptococcus lactis, is effective in preventing the outgrowth of Clostridium botulinum spores. Type A C. botulinum spores were the most resistant to the inhibitory action of nisin requiring 1000-2000 I.U. of nisin/ml for a 50% inhibition of outgrowth on TPYG agar plates. Type E spores were more sensitive requiring only 50-100 I.U./ml for 50% inhibition of outgrowth on TPYG agar plates. Type B spores displayed an intermediate level of sensitivity requiring 500-1000 I.U. of nisin/ml for 50% inhibition of outgrowth on TPYG agar plates. Similar levels of nisin were necessary to prevent spore outgrowth in TPYG broth and BHI broth over a 7-day incubation period. With prolonged incubation periods of up to 65 days in TPYG broth, spore outgrowth was observed sporadically at higher nisin levels with the type A and B spores which may indicate some decomposition of nisin with storage. Nisin levels of 5000 I.U./ml for the type A spores and 2000 I.U./ml for the type B spores and the Minnesota E spores were insufficient to prevent spore outgrowth by C. botulinurn in cooked meat medium. For the Beluga E spores, a nisin level of 2000 I.U./ml was necessary to prevent spore outgrowth in cooked meat medium. The need for higher levels of nisin in cooked medium to prevent spore outgrowth may be due to the binding of the nisin by meat particles.
TL;DR: In this article, the effect of milk, Thermophilus milk and methanol solubles of milk and Therphilus milk on the plasma cholesterol levels and hepatic cholesterogenesis using laboratory rats was studied.
Abstract: Three experiments were conducted to study the effect of milk, Thermophilus milk and methanol solubles of milk and Thermophilus milk on the plasma cholesterol levels and hepatic cholesterogenesis using laboratory rats. In experiment I, white Wistar male rats of 328g initial average weight were assigned to three dietary treatments consisting of: (1) commercial rat chow + water, (2) commercial rat chow + skim milk, and (3) commercial rat chow +Thermophilus milk. In the second experiment, the methanol solubles of whole milk and Thermophilus milk were given by gastric intubation to white Wistar male rats in six treatment groups. The methanol solubles were given at levels of 1 ml and 2 ml, and the control groups received similar quantities of H2O. In the third experiment, liver tissue from white Wistar male rats was used to study the in vitro hepatic cholesterol synthesis. Consumption of Thermophilus milk by the rats in experiment 1 resulted in a significant decrease in plasma cholesterol levels, The liver cholesterol levels were lower in the group receiving Thermophilus milk than the group receiving skim milk. Similar results were seen with feeding of methanol solubles. The in vitro hepatic cholesterogenesis was inhibited by methanol solubles from milk and Thermophilus milk, the inhibition being much more with methanol solubles from Thermophilus milk. The metabolites produced during fermentation of milk may be responsible for the hypocholesterolemic effect of Thermophilus milk.
TL;DR: In this article, the enthalpy of melting of amylose-lysolecithin complex was calculated using differential scanning calorimetry, showing that the melting of the complex can reach temperatures near 107°C.
Abstract: Amylose-lysolecithin complexes, formed in an exothermic reaction when amylose or starches are heated with water and lysolecithin, melt at temperatures near 107°C With excess lysolecithin present, formation of the maximum amount of amylose complex requires cooling after the first heating (during which gelatinization of starch takes place), and then reheating An amylose with chain length of 300 glucose units took up 14% lysolecithin; the enthalpy of melting of this complex, observed by differential scanning calorimetry, was 59 cal/g amylose Amylose content of a starch was calculated from the enthalpy of melting of its lysolecithin complex Amylose contents for potato, tapioca, lima bean, wrinkled pea, amylomaize and waxy maize starches agreed with values obtained by iodine binding Amylose contents of maize and wheat starches were larger than obtained by iodine binding, and in better agreement with amylose contents obtained by fractionation
TL;DR: The Proximity Equilibration Cell (PEC) as mentioned in this paper is a small vessel with a single sample supported on a filter paper to support the sample and at the same time allow transmission of moisture.
Abstract: Sorption isotherm data are obtained by instrumental determination of water activity at a known moisture content or determination of moisture content after equilibration against a saturated salt solution. The latter method is simpler and the salt solutions are primary standards. However, the equilibration takes a long time, one to ten weeks, depending upon food composition. Thus, the objective of this work was to devise a method that retains the saturated salt solution but accelerates the rate of equilibration. In an equilibration environment between a food product and a saturated salt slurry, the driving force is the difference in vapor pressure; therefore the faster the vapor space reaches equilibrium with the saturated salt slurry, the quicker the maximum driving force for water absorption will be applied to the sample. It was felt that a reduction in the size of the usual large desiccater to a single sample size would provide the necessary area to volume ratio. The vessel chosen was a small plastic chamber (65 mm/53 mm). In this chamber, the surface area to vapor volume ratio was 0.3101 as compared to 0.0335 for the standard desiccator. The sample was contained in a standard aluminum weighing tray modified by removing a 44 mm diameter circular section from the bottom. This was replaced with a 47 mm diameter circle of Whatman No. 1 quantitative filter paper to support the sample and at the same time allow transmission of moisture. This would allow water molecules to travel in a straight line and thus the shortest distance between the saturated salt slurry and the sample. This small vessel with a single sample supported on a filter paper will be referred to as a Proximity Equilibration Cell (PEC). Using this technique, it was found that a 2/mm deep sample of corn starch required only 6 days for complete equilibration, as compared to 21 days for the conventional desiccator. Thus, the PEC satisfied the objective by reducing time by 70%. In making comparisons with the same salts in conventional and the PEC, it was noted that the end point was higher in the latter. Evidently, absorption in case of the conventional desiccator was so slow at the end that no weight gain could be detected in 24 hr but equilibrium had not yet been attained. In contrast, the PEC equilibrated so rapidly that it allowed a closer evaluation of true equilibrium.
TL;DR: The bulk properties of powdered coffee creamer, infant formula, salt and sucrose powders at different levels of water activity were characterized by mechanical methods as mentioned in this paper, including loose bulk density, compressibility, cohesion, % irrecoverable work in compression and asymptotic modulus after stress relaxation.
Abstract: The bulk properties of powdered coffee creamer, infant formula, salt and sucrose at different levels of water activity were characterized by mechanical methods. These included loose bulk density, compressibility, cohesion, % irrecoverable work in compression and asymptotic modulus after stress relaxation. In the crystalline powders the physical characteristics generally followed the pattern established by the moisture content with an apparent critical water activity beyond which changes became drastic. In the creamer and formula which were very cohesive even in the dry form, the changes in bulk properties were generally more gradual. The rheological tests indicated that much of the physical changes in the salt and sucrose powders could be attributed to surface moisture. In the creamer and formula the plasticity of the particles material was also a major factor that affected the bulk behavior.
TL;DR: In this paper, the authors analyzed mature green and ripe bananas for moisture, protein, starch, sugars, ash, and fiber, and found that the starch granules were irregularly shaped, with spheroid and elongated forms predominating.
Abstract: Mature green and ripe bananas were analyzed for moisture, protein, starch, sugars, ash, and fiber. Ripe banana fruit contained 1.27% dietary fiber, as determined by the detergent method. Hemicellulose content was higher than that of most fruits and vegetables whereas cellulose and lignin contents were lower. The morphological and physicochemical properties of isolated starch were determined. Starch granules were irregularly shaped, with spheroid and elongated forms predominating. Both the Brabender amylograms and the two-stage swelling patterns of the starch were similar to those reported for mung bean starch.
TL;DR: Chia seed, Salvia polystachya, was analyzed as a source of oil, polysaccharide, and protein for possible use by the food industry as discussed by the authors.
Abstract: Chia seed, Salvia polystachya, was analyzed as a source of oil, polysaccharide, and protein for possible use by the food industry. Seeds were found to contain 30% oil of which more than 90% was composed of triglycerides. The fatty acid composition of the oil was found to consist mostly of C16:0, C18:0, C18:2 and C18:3. The protein content of chia seed was found to be 23.4%. A very viscous polysaccharide was isolated from the seeds. Acid hydrolysis followed by gas liquid chromatographic analysis demonstrated that xylose and arabinose were the major constituents of the polysaccharide. Seeds were found to contain niacin, riboflavin, and thiamin at a concentration of 83, 2 and 14 μg/g seed, respectively. Spectrochemical analysis showed the presence of eleven elements with calcium, potassium, and phosphorus being the most prominent. The percentage of unsaturated fatty acids, the concentration of protein and the viscosity of the polysaccharide in chia seeds would indicate that further research should be conducted to investigate possible food uses for these seeds.
TL;DR: The cultural conditions and isolation methods for Monascidin A, an antibiotic from Monascus purpureus, are reported and the dose response of Bacillus subtilis to the purified antibiotic was determined.
Abstract: The cultural conditions and isolation methods for Monascidin A, an antibiotic from Monascus purpureus, are reported. A static liquid culture medium consisting of yeast extract (0.8%) and glucose (10%) is most suitable for antibiotic production in that most of the pigments accumulated within the mycelium while the antibiotic dissolved in the culture medium. Silica gel adsorption chromatography was used to separate major pigment components from the biologically active fractions, using an eluting solvent of benzene: methanol:chloroform (30:10:9, v/v/v). Further purification using silica gel TLC plates developed with benzene:methanol:chloroform (30:20:9, v/v/v) separated the active fractions into two components, a fluorescent yellow pigment and the pale yellow antibiotic. The dose response of Bacillus subtilis to the purified antibiotic was determined and the minimum effective dosage was about 1.5 μg per 6 mm paper assay disc.