Longer Cooking Time Research Articles

Experimental investigation on simultaneous charging and discharging of an oil storage tank

An experimental setup for simultaneous charging and discharging experiments to be performed on an oil storage tank is presented. The experimental setup enables thermal energy to be stored in the storage tank as well as water to be heated up for a cooking application in a simultaneous charging and discharge cycle. Results of three different simultaneous charging and discharging cases are presented. The three different cases of simultaneous charging and discharging are; (i) an initially unstratified storage tank, (ii) an initially stratified storage tank, and (iii) an initially unstratified storage tank at the top and stratified at the bottom. The three different cases of simultaneous charging and discharging indicate that water can be boiled within 2h of the charging/discharging cycle and a sufficient amount of energy can be stored in the storage tank. It is suggested that foods which take longer cooking times can be cooked with the boiling water. The energy stored can be used to heat up or cook foods that require lower cooking temperatures. Thermal stratification in the storage is evident for all of the three cases.

Effect of line, soaking and cooking time on water absorption, texture and splitting of red kidney beans

Dry beans are rich sources of dietary fiber and phytochemicals such as flavonoids and phenolics that exhibit good functional properties. In current study line, cooking and soaking time effects were investigated on water absorption, splitting and texture of different Iranian red kidney beans to determine the best lines and the best soaking time related to them for industrial use. D81083 line had the highest level of water absorption after 24h soaking followed by Akhtar and KS31164 lines while Azna, Goli and Naz lines had the lowest level of water absorption (p < 0.05). Akhtar and Sayyad had the highest level of splitting while KS31164 had the lowest level of splitting (p < 0.05). Soaking of Akhtar line for 24h caused the highest level of water absorption accompanied with low splitting level. 24h soaking and longer cooking time is recommended for Sayyad, while 12h soaking and longer cooking time is recommended for KS31164 line. 24h soaking causes higher level of water absorption and lower level of splitting in Derakhshan line. The effects of line, cooking and soaking time on red bean texture were significant (p < 0.01).

EFFECTS OF HYDROXYPROPYL CELLULOSE ON THE QUALITY OF WHEAT FLOUR SPAGHETTI

ABSTRACTThe effects of hydroxypropyl cellulose (HPC) on the quality of the ordinary wheat flour dough and spaghetti were studied. The determination of the rheological properties of the dough showed that the peak consistency, stability time, band width (determined by a farinograph), maximum force and elasticity (determined by a texture analyzer) of the HPC sample were higher while its viscosity was lower than those of the control. Scanning electromicrographs of the samples indicated that the HPC made a network on the surface of the starch granules. Based on the results, the HPC sample had higher water absorption, longer cooking time and less cooking loss than the control. Cooked HPC sample had higher cohesiveness and breaking point strength, while it had lower adhesiveness and stringiness than the control (determined by a texture profile analyzer). It also had better organoleptic and higher general acceptability than the control.PRACTICAL APPLICATIONSIn some areas where semolina is not available for pasta production, ordinary wheat flour is one the choices. In this case, obtaining the appropriate pasta quality is a matter of concern. The results of this study can be useful for the pasta industry to produce pasta of improved quality from nonsemolina flours such as ordinary wheat or other cereal flours.

Effect of cooking time and ingredients on the performance of different starches in white sauces

The effect of white sauce ingredients and increased cooking time at 90 °C on the degree of gelatinization of corn, waxy corn, rice, potato and modified waxy corn starches was studied. The changes in pasting properties, linear viscoelastic properties, and microstructure were determined. In all the native starches in water, a longer cooking time at 90 °C caused greater starch granule swelling and more leaching of solubilized starch polymers into the intergranular space. These effects were more noticeable in the waxy corn and potato starches. The potato starch was the most affected, with complete disruption of the starch granules after 300 s at 90 °C. The microstructural changes which transformed a system characterized by starch granules dispersed in a continuous phase (amylose/amylopectin matrix) into a system with an increase in the continuous phase and a decrease in starch granules were associated with a decrease in system viscoelasticity. The elastic moduli were higher in the sauce than in the starch in water system. However, with the exception of potato starch, the white sauce showed lower viscoelasticity than the starch in water system. The white sauce ingredients decreased the effect of cooking time on the starch gelatinization process, particularly in potato starch.

Efeito da adição de suco de maracujá e tempo de cozimento sobre a qualidade de doces do albedo de maracujá em calda

O Brasil gera toneladas de resíduos de cascas e sementes de maracujá amarelo que podem ser aproveitados na alimentação humana. Os objetivos deste trabalho foram determinar os efeitos dos parâmetros do processo (volume do suco de maracujá empregado e tempo de cozimento dos albedos) sobre as propriedades físico-químicas (pH, sólidos solúveis, acidez titulável e açúcares totais) de doces em calda elaborados com a casca do maracujá, bem como sua aceitação sensorial pelos consumidores, visando o reaproveitamento dos resíduos gerados na indústria de alimentos. Utilizou-se um planejamento fatorial 2² completo para avaliação dos parâmetros e respostas. Avaliou-se a aceitação sensorial dos doces, utilizando-se escala hedônica de 9 pontos, e intenção de compra, usando-se escala de 5 pontos. Valores mais baixos de pH foram alcançados em volumes de suco e tempo de cozimento mais altos, tanto para o albedo como para a calda do doce. Maiores valores de sólidos solúveis no albedo foram encontrados em tempos de cozimento altos e em menores volumes de suco empregado. Resultados globais indicaram como condições adequadas, ao processamento do albedo de maracujá em calda, tempo de cozimento superior a 10 minutos e concentração mais elevada de suco de maracujá.

Effect of anthraquinone on brightness value and crystalline structure of pulp during soda processes

AbstractThe dependence of crystalline structure and optical properties of pulp on anthraquinone (AQ) added to the soda process at different cooking times was determined in this study. Wheat (Triticum aestevum L.) straw was used as the raw material for pulp. Soda and soda-AQ processes were selected for pulping at 80 min and 120 min. The soda-AQ process improved the yield and viscosity of pulp delignification ratio for pulping in comparison with the soda process. Crystallinity of pulp samples decreased by adding anthraquinone to the soda process because of stabilized less ordered cellulose and amorphous hemicelluloses in pulp. It was determined that crystallinity of pulp samples decreased with longer cooking time, from 80 min to 120 min, in both soda and soda-AQ processes. Monoclinic structure was dominant in pulp samples; however, the triclinic structure ratio increased in both soda and soda-AQ processes compared to raw material. It was found that brightness and lightness values in pulp samples decreased when using anthraquinone depending on the changes of the crystalline structure.

The effect of cooking on Brassica vegetables

Assessing antioxidant intake requires a food antioxidant database. However, cooking may affect antioxidant content due to antioxidant release, destruction or creation of redox-active metabolites. Here, effects of boiling, steaming and microwaving of broccoli, cauliflower, cabbage and choy-sum (Chinese cabbage) were explored by measuring antioxidant contents of raw and cooked vegetables. Cooking water was also tested. For all cooked vegetables, antioxidant content was highest in steamed > boiled > microwaved, and decreased with longer cooking time, regardless of method. All steamed vegetables had higher antioxidant contents than had matching raw vegetables. Effects were variable for boiling and microwaving. Microwaving caused greater antioxidant loss into cooking water than did boiling. Marked losses of anitoxidants occurred in microwaved cabbage and spinach. To assess food antioxidant content/intake accurately, cooking effects need detailed study. Steaming may be the cooking method of choice to release/conserve antioxidants. The cooking water is a potentially rich source of dietary antioxidants.

Pasting Properties of Ohmically Heated Rice Starch and Rice Flours

ABSTRACT: Pasting characteristics were examined for conventionally or ohmically heated rice starch and rice flours. Brown rice flour showed the greatest cooking stability and least retrogradation potential. Brown rice flour also showed the greatest pasting temperature and lowest peak viscosity, whereas commercial starch had the lowest pasting temperature. Nonstarch components of the brown rice flour, such as fat and protein, may have acted as stabilizers delaying water access into the granules and reducing swelling of the starch. Ohmic heating reduced pasting temperature for commercial rice starch, resulting in a starch that swelled faster. Furthermore, ohmic heating produced better cooking stability in white rice flour 1 and 2 than in the native sample, and caused white rice flour 2 to have less potential for retrogradation than the conventionally heated sample. At lower electric field strength (20 V/cm), ohmic heating resulted in the greatest cooking stable starches compared to higher voltages (40 and 70 V/cm) because more starch granules were disrupted from a longer cooking time, so there were fewer intact granules for pasting. Ohmic heating has been shown to alter rice starch and flour pasting characteristics with an added influence of lipids, proteins, and amylose contents.

Fermented Pigeon Pea (Cajanus cajan) Ingredients in Pasta Products

Pigeon pea (Cajanus cajan var. aroíto) seeds were fermented in order to remove antinutritional factors and to obtain functional legume flour to be used as pasta ingredients. Fermentation brought about a drastic reduction of alpha-galactosides (82%), phytic acid (48%), and trypsin inhibitor activity (39%). Fermented legume flours presented a notable increase of fat and total soluble available carbohydrates, a slight decrease of protein, dietary fiber, calcium, vitamin B2, vitamin E, and total antioxidant capacity, and a decrease of soluble dietary fiber, Na, K, Mg, and Zn contents. No changes were observed in the level of starch and tannins as a consequence of fermentation. The fermented flour was used as an ingredient to make pasta products in a proportion of 5, 10, and 12%. The supplemented pasta products obtained had longer cooking times, higher cooking water absorptions, higher cooking loss, and higher protein loss in water than control pasta (100% semolina). From sensory evaluations, fortified pasta with 5 and 10% fermented pigeon pea flour had an acceptability score similar to control pasta. Pasta supplemented with 10% fermented pigeon pea flour presented higher levels of protein, fat, dietary fiber, mineral, vitamin E, and Trolox equivalent antioxidant capacity than 100% semolina pasta and similar vitamins B1 and B2 contents. Protein efficiency ratios and true protein digestibility improved (73 and 6%, respectively) after supplementation with 10% fermented pigeon pea flour; therefore, the nutritional value was enhanced.

The Effect of Chemical and Biopulping Process on Bagasse Pulp

AbstractThe amount of sugarcane bagasse in Indonesia is abundant while the utilization is still limited. One of the alternatives for bagasse utilization is as pulp material. To minimize the waste from the pulping process, the effect of using a chemical process (with nitric acid) and a biopulping process (using Fusarium solani) were studied and measured by the percentage of α‐cellulose content in bagasse pulp. In the chemical process, the nitric acid concentration and the reaction time were varied. The pulping process was conducted at constant temperature of 102d̀C and the mixture was agitated at 900 rpm. The highest percentage of α‐cellulose content in pulp was 79.28%, obtained at the concentration of 3.5% for a reaction time of 3.5 hours. At higher concentrations and longer cooking times, the α‐cellulose decreased due to the cellulose degradation. In the biopulping process, the incubation temperature was kept at 30d̀C. The highest percentage of α‐cellulose was 65.80% obtained at an incubation time of 25 days. When compared to nitric acid pulping, biopulping is less efficient. However it has one advantage that it only uses a small amount of chemicals and, therefore, creates less pollutants.

The effects of quality grade, postmortem aging, and blade tenderization on Warner-Bratzler shear force and cookery traits of biceps femoris steaks (2001)

We used 108 top sirloin butts to determine the influence of quality grades, postmortem aging periods, and blade tenderization passes on percentages of thawing and cooking losses and Warner-Bratzler shear (WBS) force of biceps femoris muscles. Top sirloin butts that qualified for either USDA Select (SEL, n=36), USDA Choice (CHO, n=36), or Certified Angus BeefTM Program (CAB, n=36), were aged for 14 or 21 days and blade tenderized zero (0X), one (1X), or two (2X) times. Steaks with higher quality grades (CHO and CAB) aged for 21 days had lower thawing losses than steaks aged 14 days and than SEL steaks aged for 21 days. Steaks aged for 14 days and not blade tenderized (0X) had higher thawing losses than steaks aged for longer periods (21 days) and tenderized 0X, 1X, and 2X. Lower quality grade steaks (SEL) blade-tenderized 2X had longer cooking times than other quality grade×blade tenderization treatments. More blade tenderization passes (1X and 2X) for higher quality grades (CHO and CAB) appear to lower WBS values. The most tender treatments were CHO steaks blade tenderized 2X and CAB steaks blade tenderized 1X and 2X. Biceps femoris tenderness was inconsistent among all treatments, although aging, blade tenderization, and higher quality grades reduce variation. For reliable, acceptable quality this muscle should not be included in top sirloin butt steaks.

The volatile constituents of extracts of cooked spinach leaves (Spinacia oleracea L.)

The volatile constituents of spinach leaves (Spinacia oleracea L.) have been investigated by analysing two different extracts. The first extract was isolated after a short cooking time, and exhibited interesting green notes reminiscent of slightly cooked vegetables, tobacco, violet leaves and oolong tea. The second extract was collected after a longer cooking time, exhibiting meaty, smoky, phenolic, typical cooked spinach notes. In addition to the classical compounds exhibiting green notes (C6), some more tenacious substances were identified: (E)-3-methyl-2-nonen-4-one, (Z)-3-(3-hexenyloxy)-hexanal and (E)-3-(2-hexenyloxy)-hexanal. An uncommon isoprenoid, (E)-6-methyl-6-(5-methyl-2-furyl)-3-hepten-2-one, is abundant. Some alkyl-3-thiophenecarbaldehydes are new natural products and their structures have been confirmed by synthesis. Copyright © 2000 John Wiley & Sons, Ltd.

Determination of sensory, chemical and cooking characteristics of retail beef cuts differing in intramuscular and external fat

Top loin (TLS), top sirloin (TSS), and eye of round (EYS) steaks, and loin end (LRR) and blade end (BRR) rib, and eye of round (EYR) roasts were used to determine the effect of USDA quality grade, Choice or Select, external fat trim level, and internal temperature endpoint on sensory, chemical and cooking characteristics. Cuts cooked with external fat required slightly greater cooking times and had higher fat content in the lean than cuts cooked without external fat ( p < 0.05). Regardless of quality grade or external fat trim, increasing internal temperature endpoint resulted in tougher, drier cuts with longer cooking times and greater cooking loss ( p < 0.05). Choice TLS, TSS and LRR were higher ( p < 0.05) in palatability than Select, but quality grade did not affect palatability of BRR, EYS or EYR.

A differential scanning calorimetry study of wheat grain cooking

Summary A number of commercial processes involve whole grain cooking. In this study, differential scanning calorimetry (DSC) scans were taken of whole wheat grains that had been boiled or steamed for various times at either 100 d̀C or 120 d̀C. Scans were also taken of raw grains that had been soaked and equilibrated to different moisture contents. Raw grains showed peak temperatures to be dependent on moisture content, in close agreement with literature data for wheat starch/water mixtures. The two cooking methods showed different behaviour, which can be explained with reference to magnetic resonance imaging (MRI) (Stapley et al., 1997). For steamed grains with high moisture contents at longer cooking times, part of the DSC endotherm was below the cooking temperature, and conversion occurred in the cooker. DSC endotherms of steamed grains showed a clearly denned onset temperature, c. 6d̀C above the steam temperature, due to the release of latent heat. MRI shows partially boiled grains to have a high moisture content in the outer regions and an inner core of lower moisture content. The peak temperatures observed by DSC were similar to those expected of soaked grains with the same moisture contents as that of the core. It is postulated that the inner core contains unconverted starch, and that conversion has been achieved in the outer regions. The specific heat capacity for each grain was also measured, and correlated well with moisture content, but was not strongly influenced by the grain treatment.

Characteristic Flavor Components in the Brew of Cooked Clam (Meretrix lusoria) and the Effect of Storage on Flavor Formation

The odorants in the brew of cooked clam (Meretrix lusoria) were separated by adsorption into Tenax TA resin. An analysis by GC and GC−MS enabled 49 compounds to be unambiguously or tentatively identified. Among them, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) (caramel-like), maltol (sweet), 2-acetyl-2-thiazoline (roasted), 2-acetylthiazole (popcorn-like), and 3-methylthiopropanal (boiled potato-like) were determined as the main potent odor compounds by an aroma extract dilution analysis. Since the concentrations of these compounds were increased with the longer cooking time, it was considered that the increase of these compounds was deeply related to the formation of the characteristic odor in the brew of cooked clam. Furthermore, by keeping the body of the clam at 4 °C for periods of 30 min, 2 h, 12 h, and 24 h before cooking, the formation of maltol and DMHF was increased significantly with increasing length of storage time, thus enhancing the flavor of the cooked clam. Keywords: Cooked clam; potent odorant; Tenax TA adsorption; DMHF; maltol; storage

THE EFFECT OF FREEZING RATE, STORAGE AND COOKING ON SOME B-VITAMINS IN BEEF AND PORK ROASTS

The effects of freezing rate, storage and cooking on some B-vitamins in beef and pork roasts were studied. Meat samples frozen to an internal temperature of -20C in air blast at -30 or -40C (5 m/s) within 4 h or 3.3 h, respectively, had no significant (P > 0.05) drip or B-vitamin losses in the frozen-thawed-uncooked (FTU), frozen-thawed-roasted (FTR), and frozen-roasted (FR) samples. The retention of thiamin, riboflavin, niacin and cooking losses in samples which were stored either at -10 or -25C for 30 to 90 days ranged from 58 to 63%, 73 to 79%, 83 to 87%, and 20 to 26%, respectively, in pork and 72 to 78%, 72 to 83%, 83 to 93%, and 16 to 22%, respectively, in beef. The frozen-thawedrefrozen (FTRF) pork samples which were roasted after 30 or 90 days of frozen storage had higher B-vitamin losses (31 to 59%) and cooking losses (42 to 63 %). The vitamins remaining in the drippings were about 3 to 14%. Also, roasting of samples from the frozen state caused increased cooking losses, reduced vitamin retention, and longer cooking time when compared with samples roasted from the raw or thawed states.

EFEITO DE MODOS E ÉPOCAS DE APLICAÇÃO DE GESSO E CALCÁRIO SOBRE A CULTURA DO FEIJOEIRO (Phaseolus vulgaris L.) cv. CARIOCA-80

Instalou-se sobre um latossolo vermelho-escuro textura média, um experimento cujo objetivo foi avaliar a influência de modos e épocas de aplicação de gesso e de calcário sobre algumas características nutricionais e tecnológicas da cultura do feijoeiro irrigado. Utilizou-se no experimento o delineamento em blocos casualizados em esquema fatorial (4x3)+2 com quatro repetições, correspondendo a 4 modos de aplicação de gesso e/ou calcário, 3 doses de gesso e 2 tratamentos adicionais. Os resultados mostraram que: o uso do gesso proporcionou maiores teores de Ca nos grãos e consequentemente maior tempo para o seu cozimento. A associação gesso e calcário propiciou aumento no teor de S das folhas e também no peso de 100 grãos, quando comparado à utilização de apenas gesso. A relação de hidratação diminuiu com o aumento das doses de gesso quando utilizou-se os modos de aplicação M1 (gesso aplicado no solo 45 dias antes da semeadura) e M2 (gesso e calcário aplicados conjuntamente aos 45 dias antes da semeadura).

Hard‐to‐cook phenomenon in common beans‐ influence of growing location and hardening procedures

SummaryTwo accelerated hardening procedures (storage for up to 4 months, and soaking in acetate buffer for up to 5 h) for testing beans were examined and compared, so that new cultivars prone to the hard‐to‐cook (HTC) defect may be identified. Bean hardness was measured by means of the Mattson bean cooker, and by measuring puncture force. Two imporant common bean (Phaseolis vulgaris) cultivars were grown in two locations differing in soil Ca and Mg content. Those from the high Ca site had longer cooking times, which increased more rapidly on accelerated storage and in the soaking tests. The results of this preliminary study suggest that the acetate soak hardening procedure is worthy of further investigation as the basis of a rapid test for the presence of the hard‐to‐cook defect in new cultivars.

Effects of temperature, patty thickness and fat content on the production of mutagens in fried ground beef

The high-pressure liquid chromatography (HPLC) profiles of mutagenic components were compared for extracts of ground beef patties fried at 200, 250 and 300°C for 6 min/side. The HPLC profiles of the mutagenic samples were similar, although total mutagenic activity in Salmonella typhimurium TA 1538 was roughly four times as high after the 300°C than after the 200°C frying. Six mutagenic peaks were analysed quantitatively at different temperatures and meat thicknesses. Two major components, 2-amino-3,8-dimethylimidazo[4,5- f]quinoxaline and 2-aminotrimethylimidazo[4,5- f]quinoxaline, and a minor component, 2-amino-3-methylimidazo[4,5- f]quinoline (IQ), were all present at the three different temperatures. Thus, in general, cooking temperature seems to have a major effect on the quantities of mutagens produced but not on their HPLC profiles. The thickness of the meat patty did not affect the total yield of mutagens except at longer cooking times (8–10 min/side) and, in general, neither did it affect the HPLC profiles of the mutagenic components. Total mutagenic activity increased with increasing cooking times. Increasing the fat content lowered the total mutagenicity, with 150,000 revertants/kg of fresh beef at 30% fat compared with 230,000 revertants/kg at 15%, but had little effect on the mutagenicity due to IQ.

Evaluation of some quality characteristics in cassava storage roots

The susceptibility to physiological deterioration and the hardness (penetration) of fresh peeled cassava roots as well as the cooking time, taste and texture of cooked roots of four (one local and three promising) cultivars at four plant ages (6, 8, 10 and 12 months) were evaluated. Variety or cultivar, plant age and their interactions significantly affected all these parameters. Roots produced by the local cultivar (M Col 113) had lower DM contents and susceptibility to physiological deterioration, a longer cooking time and higher penetration measurements than the promising cultivars. Physiological deterioration and penetration values tended to decrease, whereas cooking time increased as the plants became older. The variation in correlation coefficients between quality and chemical parameters among the different cultivars was substantial, with no correlation being significant in all four cultivars. The experimental results demonstrate the great variability among cassava cultivars in the root quality factors.