Degree Of Cooking Research Articles

Extrusion‐Cooking of Sorghum Containing Different Amounts of Amylose

ABSTRACTThree sorghums containing different amounts of amylose (12.2, 21.5, and 26.7%) were decorticated, ground and extruded at three extrusion moisture levels (17, 32, and 45%). Highly expanded and brittle sorghum extrudates with high degrees of starch cooking were produced at 17% extrusion moisture content. All sorghum extrudates exhibited a V‐amylose x‐ray diffraction pattern. Functional characteristics, such as expansion, enzyme‐susceptible starch ratio, and water solubility, indicated that low amylose extrudates were more cooked than other varieties. Thin porridges prepared from extruded sorghums had an intermediate consistency, smooth texture, roasted flavor and white color. Thin porridges (atoles) from extrudates containing 21.5% amylose, were preferred by a sensory panel over those from extrudates containing 12.2 and 26.7% amylose.

Glycemic response to pasta: effect of surface area, degree of cooking, and protein enrichment.

To see whether food form, the degree of cooking, or protein enrichment affected the glycemic response to pasta, we gave test-meal breakfasts to 13 diabetic patients. Macaroni had a significantly greater glycemic index (GI) (68 +/- 8) than spaghetti (45 +/- 6, P less than .01); the GI of star pastina was intermediate (54 +/- 6). The GI of spaghetti was not significantly affected by cooking for 5 or 15 min (45 +/- 6 and 46 +/- 5, respectively), or by protein enrichment (38 +/- 4). The GI of spaghetti was similar in 11 non-insulin-dependent and 6 insulin-dependent diabetic patients (49 +/- 7 compared with 57 +/- 8). We conclude that different types of pasta may produce different glycemic responses but that these are not necessarily related to differences in cooking or surface area.

Thermomechanical properties of beef muscle

Differential scanning calorimetry (DSC) was used to follow the three major endothermic transitions (T 1, T 2 and T 3) of beef muscle during heating. Borchardt and Daniels reaction kinetics were used to predict the three time and temperature treatments required to sequentially eliminate each transition. Longissimus dorsi and semimembranosus muscles were removed from beef carcasses suspended by Achilles tendon or pelvis. Samples prepared by heating for 5 min at 57°C (I), 70°C (II) and 81°C (III) were assessed by sensory panel for tenderness, juiciness and residual connective tissue. Weight loss, Warner-Bratzler (W-B) shear and microstructure using transmission electron microscopy (TEM) were also determined. The I treatment showed a significant difference in tenderness and residual connective tissue between muscles, but not between contraction states. The II treatment produced collagen shrinkage and a significant drop in W-B shear and residual connective tissue, coupled with increased tenderness in semimembranosus muscle. An increased W-B value, decreased juiciness, increased weight loss and a reduction in sarcomere and A-band length accompanied the III transition. Muscles from carcasses that had been suspended by the pelvis were found to be significantly more tender than the same muscles from Achilles hung carcasses. It is concluded that DSC is capable of determining amount of protein denaturation and, hence, degree of cooking.

Degradation of Wheat Starch in a Single‐Screw Extruder: Mechano‐Kinetic Breakdown of Cooked Starch

ABSTRACTWheat starch was processed in a 19 mm diameter split‐barrel laboratory extruder under varying conditions of barrel temperature (79–121oC), screw speed (50, 100 rpm) and moisture content (25, 30%). Final product and samples removed from along the barrel length were examined for changes in molecular size by dilute solution viscometry. Final products were also examined for paste viscosity and estimated degree of cook. A mathematical model was developed which relates the residence time of the starch in the barrel, the nominal shear stress acting on the starch and the degree of cook of the product to the extent of molecular degradation of the starch. Solution viscometry was found to be more rapid than gel permeation methods previously used to determine the extent of molecular changes.

Thermomechanical Properties of Beef Muscle

Abstract Differential scanning calorimetry (DSC) was used to follow the three major endothermic transitions (T 1 , T 2 and T 3 ) of beef muscle during heating. Borchardt and Daniels reaction kinetics were used to predict the three time and temperature treatments required to sequentially eliminate each transition. Longissimus dorsi and semimembranosus muscles were removed from beef carcasses suspended by Achilles tendon or pelvis. Samples prepared by heating for 5 min at 57°C (I), 70°C (II) and 81°C (III) were assessed by sensory panel for tenderness, juiciness and residual connective tissue. Weight loss, Warner-Bratzler (W-B) shear and microstructure using transmission electron microscopy (TEM) were also determined. The I treatment showed a significant difference in tenderness and residual connective tissue between muscles, but not between contraction states. The II treatment produced collagen shrinkage and a significant drop in W-B shear and residual connective tissue, coupled with increased tenderness in semimembranosus muscle. An increased W-B value, decreased juiciness, increased weight loss and a reduction in sarcomere and A-band length accompanied the III transition. Muscles from carcasses that had been suspended by the pelvis were found to be significantly more tender than the same muscles from Achilles hung carcasses. It is concluded that DSC is capable of determining amount of protein denaturation and, hence, degree of cooking.

Component Interactions in the Extrusion Cooking Process: Influence of Process Conditions on the Functional Viscosity of the Wheat Flour System

ABSTRACTWheat starch, vital gluten and wheat flour solubles were processed in combination, in a single screw extruder. The paste viscosity profile and degree of cook of the starch component were used to assess interactive effects. The composite of all 3 components, simulating a wheat flour, was more cooked and gave thicker pastes than wheat flour itself when processed under the same extrusion conditions. The data suggest that the integral structure of wheat flour particles imparts a greater resistance to water penetration and cooking than when the individual components exist at random in a composite formulation.

Myofibrils of cooked meat are a continuum of gap filaments

When cooked meat is subjected to high degrees of stretch it becomes apparent in high magnification electron micrographs that A-filaments have ceased to exist. The A-band is filled with a coagulum of actomyosin. Fragmentation of this coagulum during stretch reveals an array of fine filaments (identified as gap filaments). This result is obtained irrespective of rigor temperature, state of contraction or degree of cooking. If the meat is first aged, the gap filaments surviving in the I-band are too weak to open up the A-band. The results show that myofibrils in cooked meat are entirely dependent on heat-stable gap filaments for structural continuity and tensile strength. Theories of meat tenderness must be revised accordingly.

LITERATURE ABSTRACTS

GENERAL PRINCIPLES: Effects of “Ante Mortem” Treatment with Intraperitoneal Injections of Calcium Gluconate and Magnesium Sulphate on Tenderness of Frozen Lamb. E. Garcia‐Matamoros, A. Moral, F. Jimenez and F. Senz.GENERAL PRINCIPLES: Structural ‐ Mechanical Properties of Fresh Raw Meat, and Technologically Caused Changes. I. Kieszling and H. J. Raeuber.GENERAL PRINCIPLES: Gelation of Reconstituted Whey Powders by Heat. R. M. Hillier, R. L. J. Lyster and G. C. Cheeseman.GENERAL PRINCIPLES: Study of the Flow Behavior in the Low Flow Region of Skim Milk Solutions. K. Kubota, T. Matsumoto, K. Suzuki and H. Hosaka.INSTRUMENTATION AND METHODOLOGY: Apparatus for Determining the Rheological Properties of Meat Products. V.D. Kosoi, V.A. Gonotekii, S.N. Shevchenko, O.V. Zvonov, V.M. Yakushin and O.N. Kashelkin.INSTRUMENTATION AND METHODOLOGY: Instrument for Texture of Small Curd Cottage Cheese. A. Perry and P. A. CarroadINSTRUMENTATION AND METHODOLOGY: A Nondestructive Test for Determination of Optimum Maturity of French (Green) Beans (Phaseolus vulgaris). H.S. Ramaswamy, S. Ranganna and V.S. Govindarajan.INSTRUMENTATION AND METHODOLOGY: Viscoelastic, Dielectric and Piezoelectric Behavior of Solid Amylose. K. Nishinon and E. Fukoda.INSTRUMENTATION AND METHODOLOGY: Note on a Method for Measuring Breakage Susceptibility of Shelled Corn during Handling. B. S. Miller, J. W. Hughes, R. Rousser and Y. Pomeranz.INSTRUMENTATION AND METHODOLOGY: An Instrument for Measuring the Springiness of Chhana. V. K. Gera and G. S. Rajorhia.INSTRUMENTATION AND METHODOLOGY: Use of a Penetrometer to Determine Firmness of Emulsion‐type Sausage. L. Andersson and K. E. Hansson.INSTRUMENTATION AND METHODOLOGY: Penetrometer to Evaluate Sausage Meat Quality. V. M. Gorbatov, A. V. Gorbatov, V. D. Kosoi and O. V. Zronov.INSTRUMENTATION AND METHODOLOGY: An Application of the Ultrasonic Pulse Echo Technique to the Measurement of Crispness of Biscuits. M.J.W. Povey and C.A. Harden.OBJECTIVE MEASUREMENT: Behaviour of the Mechanically Separated Flesh of Some Common Fish Species of the Mexican Shrimp By‐catch During Storage at —20%. M.A. Tableros*and R.H. Young**.OBJECTIVE MEASUREMENT: Sheer Stress Relaxation of Wheat Flour Dough and Gluten. L. Bohlin and T.L‐G. Carlson.OBJECTIVE MEASUREMENT: Changes in the Mechanical Properties of Rhein Riesling Grapes During Ripening. J. Frybort.OBJECTIVE MEASUREMENT: Storage Temperature and the Dynamic Elasticity of Apples and Potatoes. J. van Lancker.OBJECTIVE MEASUREMENT: Objective Measurement of Cottage Cheese Texture. P.C. Vasavade.OBJECTIVE MEASUREMENT: Subjective and Objective Assessments of the Degree of Cooking of Potatoes Heated by Different Methods. R. Collison, K. Johnson, O.O. Okikiolu and A. West.OBJECTIVE MEASUREMENT: A Rapid Batter Expansion Method for Testing the Baking Quality of Wheat Flours. Nawab Khan and Manzoor Elahi.OBJECTIVE MEASUREMENT: Emulsifying Properties of Undenatured Potato Protein Concentrate. F. Holm and S. EriksenOBJECTIVE MEASUREMENT: Precision in the Measurement of Meat Texture. E. Dransfield and H.J.H. Mac‐Fie.RELATIONSHIP TO STRUCTURE: The Carrageenan from Iridaea undulosa B.; Analysis, Fractionation and Alkaline Treatment. M. C. Matulewicz and A.S. Cerezo.RELATIONSHIP TO STRUCTURE: The Textural Quality of Cooked Potatoes.I. The Relationship of Cooking Time to the Separation and Rupture of Potato Cells. M. Nonaka.RELATIONSHIP TO STRUCTURE: Relationship Between Structure and Rheological Behavior of Juices and Purees of Fruits and Vegetables. T. R. Garcia and A. I. Buron.RELATIONSHIP TO STRUCTURE: The Influence of the Structure of Starch on Its Rheological Properties. D. Howling.RELATIONSHIP TO STRUCTURE: Relationship Between Covalent Structure of Xanthomonas Polysaccharide (Xanthan) and its Function as a Thickening, Suspending and Gelling Agent. K. C. Symes.

Subjective and objective assessments of the degree of cooking of potatoes heated by different methods

SummaryStandard potato slices were heated for various periods of time by three different methods: boiling water, steam under pressure, and a microwave oven. After heating, the internal temperature was measured together with textural characteristics to assess the degree of cooking, using both a taste panel and an Instron 1140 machine.It was found that for a given method of heating the taste panel score is related to the instrumental measurements of rupture load and rupture energy. It was also found that the degree of cooking of a potato does not depend solely on the internal temperature reached, but is also dependent on the heating method and particularly on the rate of heating.

Gelatinization, Pasting Characteristics and Cooking Behaviour of Egyptian Rice Varieties in Relation to Amylose and Protein Contents

AbstractGelatinization and pasting characteristics of milled powder of shortgrain rice varieties gave Amylograms which generally exhibited lower gelatinization temperatures and longer gelatinization times than long‐grain varieties. Galatinization temperatures and peak viscosities were independent of amylose and protein contents; the drop in viscosity at 94 °C generally was negatively correlated with protein content but positively correlated with amylose content. The maximum volume‐expansion ratio and water absorption ratio for short‐grain varieties were lower than with the long‐grain varieties, and the two ratios were also related to the amylose content. Apparently cooking period was the principle factor for controlling the degree of cooking.

Some Aspects of the Cooking Degree Numbers of Unbleached High-Yield Soda Bagasse Pulp

Some Aspects of the Cooking Degree Numbers of Unbleached High-Yield Soda Bagasse Pulp

Extensibility, strength and tenderness of beef cooked to various degrees

AbstractThe response to loading of strips of ox sternomandibularis muscle varies greatly with degree of cooking. In raw or lightly cooked strips a yield point is reached where the myofibrils fail. Within this range, the yield point is independent of degree of cooking, and at 1.4 kg/cm2 is well below the tension which can be developed in the pre‐rigor muscle (2.3 kg/cm2). On cooking, the yield point vanishes between 10 and 40 min at 70°C and the strips behave more elastically. This degree of heating coincides with the sharpest change in shrinkage and other properties. By using strips in which the myofibrillar component has been destroyed by alkali, and others in which collagen has been destroyed by long cooking, an attempt has been made to separate the contributions of these components. Between 60 and 80°C a fall in connective tissue strength is matched by a rise in myofibrillar strength, maintaining a constant overall value of ca 5 kg/cm2. Both components become more extensible and stretch in unison, until they fail together. After cooking at 100°C, only the myofibrillar component survives (ca 3 kg/cm2). Shear force values are generally in line with these results, but show a dip on cooking at 60°C, due to accelerated ageing. It is suggested that gap filaments may determine the tensile strength of the raw or cooked myofibril.

KINETIC STUDIES ON COOKING OF RICE

ABSTRACTThe mechanism of cooking rice was investigated in this study. The rheological method using the parallel plate plastometer was adopted for measurement of the degree of cooking. The range of temperatures measured ran from 75–150°C. Experimental results showed that cooking rate followed the equation of a first order chemical reaction. We designated the proportional constant as the cooking rate constant, but the slope of Arrhenius plots of the cooking rate constants changed around 110°C. The activation energy of cooking at temperatures below 110°C and above 110°C was about 19,000 and 8,800 cal/mol respectively. The influences of water soaking time before cooking were also studied. We concluded that the cooking process comprises two mechanisms; at temperatures below 110°C the cooking rate is limited by the reaction rate of rice components with water; and at temperatures above 110°C it is limited by the rate of diffusion of water through the cooked layer toward the interface of uncooked core where the reaction occurs. The reaction rate constant and the diffusion coefficient of water were calculated by assuming the core model or shell‐type model.

Preparation of Vanillin from Sulphite Waste Liquor. Part. 1

Oxidation process of sulphite waste Liquor to produce vanillin has been investigated about four samples, which were produced from Pinus densiflora Sieb. et Zucc. through various degree of cooking. The oxidation was carried out at a temperature range of 80 to 170°C and under the normal as well as a high pressure.Sulphite waste liquor, in which the concentration of cuastic soda was controlled to be 8 g per 75 cc, was brought into an autoclave, into which oxygen was introduced under a pressure of 10 atm., and heated at a temperature of 170°C. for three hours under rotation. The yield of vanillin thus obtained was 19.4 per cent with respect to the amounts of lignin in the waste liquor used. The later was about 5g per 75cc of it.Next, the whole process was divided into two steps, one is heating process and the other oxidation process, and the waste liquor is subjected to this two processes one after another, Thus waste liquor in the autoclave, into which oxygen was introduced under a pressure of 10 atm., was caused to be oxidized at a temperature of 90 to 95°C under catalytic action of nickel gauze and then heated at a temperature of 170°C after oxygen was removed. The yield of vanillin obtained by this method was 12.65 per cent. On the other hand, the yield of vanillin was 9.3 per cent when waste liquor was firstly heated at a temperature of 150°C for half an hour and then, as the second step, oxidized at a temperature of 100°C in the presence of cupper wire as a catalyst by introducing oxygen under the normal pressure. The same result was also attained when the first heating process was carried out at a temperature of 170°C for five minutes and was followed by the same treatment as above. However, the yield was about 7 per cent when the first heating process at a temperature of 150°C was followed by the oxidation process by cupric oxide at a temperature of 90°C under a normal pressure. In oder to keep effective contact of oxygen with the reaction solution, a new design of apparatus for oxidation process by oxygen was deviced, which might be very interesnitgf rom the industrial point of view. Nickel and cupper proved to be superior catalysts for oxidation by oxygen.The yield of vanillin obtained from sulphite waste liquor which had been produced through lower degree of cooking was larger than that of vanillin from waste liquor produced through higher degree of cooking. This suggests the facts that the degree of cooking of pulp has influence on the yield of vanillin prepared from waste liquor of it.When Tomlinson-Hibbert's method was applied to the sulphite waste liquor employed in this investigation, the yield of vanillin was only 1.5 per cent.

On the Manufacture of Pulp by Ammonium Sulphite Process. (No. 3)

The cooking of Abies Sachaliensis by ammonium bisulphite is investigated, and at the same time the cooking is compared with those by Na base bisulphite and neutral ammonium sulphite. The results are as follows : 1) The cooking velocity by the liquor of ammonium bisulphite, showing its pH 2.8, is greater than that of neutral ammonium sulphite. The complete pulping is performed by the liquor more than 5 % SO2 concentration at 140°C, or more than 2.5 % SO2 concentration at 150°C in the case of the cooking time is limitted to 4 hours. The cooking ability of NH3 base is superior to Na base. To have the same cooking degree in the case of using Na base compared with that of NH3 base, the cooking temperature must be elevated about 610°C, when another conditions are unchanged. The resulting pulp of Na base shows the almost same properties as the NH3 one, excepting some superiorities in its colour and some greater folding number than the latter one. (Japanese report, Fig. 1, 2, 3, 12) 2) The elongation of the cooking time from 4 to 10 hours is correspondent to the elevelation of the cooking temperature about 10°C, and the properties of 10 hours cooking pulp resulted, excepting some lower hemicellulose content, are the same with those of 4 hours cooking pulp. (Japanese report, Fig. 1, 2, 3, 9, 10).3) Considering from the degree of SO2 consumption, it is decided that the digestion mechanisms by SO2 in both neutral and acidic mediums must be the same, inspite of the observed difference in both reaction velocities. (Japanese report, Fig. 2, 3) 4) Ammonium bisulphite pulp shows some lower holocellulose content, appreciable higher lignin content and some lower Roe number in comparison with the neutral ammonium sulphite pulp. (Japanese report, Fig. 5, 6, 7) 5) Mannan content of the pulp is 22.5 % lower than the neutral cooked pulp having the same yield. (Japanese report, Fig. 10) 6) The pulp shows the maximum mechanical strength at about 50% yield, and it shows breaking length 12 km, folding number 400 times and specific bursting strength 9, showing superiority in comparison with the maximum value of neutral cooked pulp. But in the range of semichemical pul, the mechanical strength decreases.

ON THE STRENGTHS OF KP DIFFERENT FROM DEGREE OF DIGESTION

The writers have, in mill scale, made some kinds of K.P. different from the degree of digestion, and examined the change in strength properties to various freenesses. According to the results, tensile and bursting remain highest at about 10-12 of Roe Value. The drop inclination of stpengths is so little for harder pulp, being few differences between them. But, tearing becomes stronger with advanced cooking degree within the limits of less-over-cooking.

Polymerisation of Tung Oil. V. Effects of Treated Fatty Oils upon the Gelation of Tung Oil

Abstract 1. The gelation—preventing actions of oxidised and polymerised linseed oil were measured. The value of x∞ increases with the increasing degree of cooking and the value for oxidised oils is always greater than that for polymerised oils of the same cooking degree. 2. Perilla oil was oxidised at 100°C., 200°C. and 300°C. to the degrees of iodine values 170, 150, 140 and the effects upon the gelation were meas？red. In the cases of oxidised oil prepared at 300°C. the relation of 1⁄t∼x was linear and the value of x∞ increase according to the increase of cooking degree. In the cases of oxidised at 100°C. and 200°C. curved lines were obtained. This tendency is supposed to be due to the peroxide contained in it. 3. The effect of benzoyl peroxide also was examined. Benzoyl peroxide has a strong gelation accelerating action. The effect of perilla oil added with benzoyl peroxide is similar to that of perilla oil oxidised at low temperature. 4. The gelation—preventing action of brominated oils is very strong and the value of x∞ is less than 4%. Therefore, these substances can be used as a strong gelation—preventing agent.