Precooking Treatment Research Articles

Precooking treatments affect the sensory and tensile properties of autoclaved recooked noodles via moisture distribution and protein structure.

To improve the quality of autoclaved recooked noodles (ARNs), this study explored the effects of precooking on the sensory and tensile properties of ARNs from the perspectives of changes in protein structure and water distribution. The results showed that the ARNs of two kinds of pretreatments (Boiling 2min, Boiling 1min+Steaming 2min) presented the best sensory quality (average score≥7.50) and high tensile properties (tensile distance≥45.24mm). After autoclaving and recooking, the proportion of tightly bound water increased by 11.30%-12.52%, resulting in stronger water-solid interaction. The results of laser confocal microscopy (CLSM) proved that a strengthened gluten network (protein percentage area≥40.28%; junction density≥10.96×10-4) appeared. Therefore, appropriate precooking treatment could effectively improve the sensory quality and tensile properties of ARNs by enhancing the tightly bound water ratio and strengthening the gluten network.

The Quality Characteristics of Ready-to-Eat Empal Gentong Affected by Meat Pre-Cooking

The purpose of this research was to examine the effectiveness of pre-cooking treatments on the quality characteristics of ready-to-eat (RTE) empal gentong. Raw beef meat was pre-cooked in water bath at 90°C for 0 min (C), 10 min (T1), 20 min (T2), and 30 min (T3) prior to retorting process at 121°C and pressure at 70,000 Pa. Results showed that pre-cooking treatments in all treated samples could reduce fat contents in empal gentong’s meat by 0.02% (T1), 0.28% (T2), and 1.13% (T3) respectively. Highest precooking time tends to increase the pH and CIE a* values. However, CIE b* values, water holding capacity, and sensory analysis were not affected by pre-cooking duration which must have been affected by sterilization process after pre-cooking. In conclusion, pre-cooking treatment before sterilization in producing empal gentong is a probable technique to reduce its fat content and improve its physical quality. A specific treatment at 90°C for 10 min is recommended to achieve optimum quality of RTE empal gentong’s meat.

Effects of electrohydrodynamic drying and prefreezing pretreatment on physicochemical and functional properties of potato flours

In this paper, the effects of electrohydrodynamic drying and different pretreatments such as prefreezing (washing, prefreezing at −20℃ for 24 hr, thawing, slicing, color care, and drying) and precooking (washing, slicing, color care, precooking, and drying) on the physicochemical and functional properties of potato flours were evaluated and compared with a control sample (washing, slicing, color care, and drying), using standard methods. The results revealed that in the early stage of electrohydrodynamic drying, the drying rate of potatoes gradually increased with the increase of voltage. And the oil absorption index and water solubility index of the potato flours prepared by 20-KV drying voltage were greater than other voltages as a whole. Compared with the control group and precooking treatment, the drying time of prefreezing potatoes reduced by 1–2 hr. The characteristics of potato flours prepared by prefreezing treatment were higher than that of the control group and precooking treatment, such as amylose content, water absorption index, swelling power, and viscosity. The study showed that pretreating potato tuber using prefreezing prior to electrohydrodynamic drying gave the best quality potato flour compared to the control sample. Practical applications Precooking is the main pretreatment method for preparing potato flour. After precooking, the potato flour has been partially gelatinized, and the gelatinized potato flour is difficult to meet the processing requirements. Electrodynamic drying is a new type of nonheat treatment drying method, which can avoid the deterioration of the quality of potato dehydrated products caused by high temperature. And the prefreezing treatment has not been applied in the production of potato flour. Electrohydrodynamic drying combined with prefreezing treatment may help to change the functional properties of potato flours and expand the diversity of potato flours. This drying mode will provide a useful reference for the drying research of other materials.

Optimizing pre-cooking treatment condition for reducing lead (Pb) content in Seaweed (Gracilaria sp.)

Seaweeds are increasingly used in Indonesian cuisines due to their nutritional value and health benefits. In contrast to these benefits, they accumulate lead during their growth and exhibit potential health risks upon ingestion. To overcome these risks, some appropriate pre-cooking treatments are desired to reduce lead content. Sample of Gracilaria sp. will be treated by soaking before cooking. This study applied the Taguchi method to determine optimum pre-cooking treatment conditions to reduce the level of lead in Gracilaria sp. The control factors included soaking temperature, time reaction, potential of hydrogen and water volume are used for this research. The levels of lead were determined by Atomic Absorption Spectroscopy (AAS). After these processes, lead contents were found to be successfully reduced and the results show that the optimal conditions during the soaking process can reduce the levels of lead of Gracilaria sp. until 56%.

Effects of Pre-cooking Process with Acetic Acid and Citric Acid on the Lead (Pb) Concentration in Rice

Rice is one of the most highly consumed food stuff all-around the world. In keeping with this, produced rice of many regions of the world contain high content of the lead (Pb). The present research was done to study the effects of the pre-cooking process of rice with acetic acid and citric acid on the concentration of lead. Rice samples were divided into 5 different pre-cooking treatment groups of soaking in acetic acid 1% and soaking in citric acid 1% (2hrs), boiling with acetic acid 1% and boiling with citric acid 1% (20 min) and finally 6 times rinsing with deionized water. Then, measurement of lead remains was done using the atomic absorption optical spectrometer equipped with detector of graphite furnace with deuterium lamp. The mean concentration of lead in primary rice samples without any processing operation was 87±4.8ppb. The mean concentration of lead in rice samples processed with soaking in acetic acid, soaking in citric acid, boiling with citric acid, boiling in acetic acid and finally 6 times rinsing with deionized water were 55±3.8, 14±1.6, 32±2.4, 14±1.1 and 30±0.5ppb, respectively. The highest reeducation percent of lead in rice samples was obtained in both soaking with citric acid and boiling with citric acid (84%). In keeping with the high concentrations of lead in studied rice samples, obtained concentrations were lower than allowed limit of lead announced with the international standard organization of Iran (150ppb). Boiling and soaking of rice samples with citric acid 1% in home can be a convenient and fast way to reduce the concentration of lead in rice samples.

Effect of Pre-cooking Conditions on the Quality Characteristics of Ready-To-Eat Samgyetang.

The aim of this study was to examine the effectiveness of pre-cooking conditions on the quality characteristics of ready-to-eat (RTE) Samgyetang. Raw chickens were steamed under the different conditions of 50℃/30 min (T1), 65℃/30 min (T2), 85℃/30 min (T3), and 90℃/10 min (T4) prior to retorting at 120℃ for 65 min. The results showed that pre-cooking conditions in all treated samples could reduce fat contents in breast and leg meats by 8.5-11.7% and 10.0-11.0% compared to the control, even though there were no significant differences among treatments (p>0.05). The L* and b* values of breast and leg meats treated with the higher temperature and longer time conditions were significantly higher than the control (p<0.05), while a* values tended to decrease despite of not to a significant extent (p>0.05). Moreover, apparent viscosity and water soluble protein showed insignificant differences (p>0.05) among the samples as a result of the retorting process, which might have more negative influences on the quality. T2 samples obtained significantly the highest average Quantitative Descriptive Analysis (QDA) score and transmittance value, representing the most clear broth among the samples, compared to the control. On the other hand, T3 showed the highest cooking loss among the treatments and the lowest QDA scores among the samples. In conclusion, pre-cooking treatment prior to retorting in manufacturing Samgyetang is a plausible way to reduce its fat content. A pre-cooking condition at either 65℃ for 30 min, or 90℃ for 10 min are recommended for producing Samgyetang with optimum quality.

Legume-Fortified Pasta. Impact of Drying and Precooking Treatments on Pasta Structure and Inherent In Vitro Starch Digestibility

The low glycaemic index of pasta can be attributed to its specific structure. A change in pasta structure can therefore lead to a change in its starch digestibility. The use of drastic drying conditions or the addition of non-traditional ingredients to durum wheat pasta was already demonstrated to affect its structure, leading to a modification of its starch digestibility. However, the combining effect of using different technological treatments and different raw materials on pasta structure and consequences on its starch digestibility pasta are still unknown. The objective of this work was therefore to determine the impact of different technological treatments on the structure and the in vitro starch digestibility (i.e. rapidly available glucose value) of legume-fortified pasta. Legume-fortified pasta was prepared from 65% of durum wheat semolina and 35% of split pea or faba bean flour. Four different technological treatments were applied: drying at low temperature of 55 °C (LT), drying with the application of a very high temperature of 90 °C at low moisture content (VHT.LM), lyophilisation, and precooking followed by LT drying. Legume-fortified pasta dried at LT served as a reference. Lyophilisation induced a higher starch digestibility that could be attributed to the high porosity of pasta and the weakness of its protein network. In contrast, VHT.LM drying and precooking treatment led to a lower in vitro starch digestibility, probably as a result of the strengthening of the protein network at a macromolecular level, protecting starch from enzymatic attack.

Application of Classification and Regression Trees for Sensitivity Analysis of the Escherichia coli O157:H7 Food Safety Process Risk Model

Microbial food safety process risk models are simplifications of the real world that help risk managers in their efforts to mitigate food safety risks. An important tool in these risk assessment endeavors is sensitivity analysis, a systematic method used to quantify the effect of changes in input variables on model outputs. In this study, a novel sensitivity analysis method called classification and regression trees was applied to safety risk assessment with the use of portions of the Slaughter Module and Preparation Module of the E. coli O157:H7 microbial food safety process risk as an example. Specifically, the classification and regression trees sensitivity analysis method was evaluated on the basis of its ability to address typical characteristics of microbial food safety process risk models such as nonlinearities, interaction, thresholds, and categorical inputs. Moreover, this method was evaluated with respect to identification of high exposure scenarios and corresponding key inputs and critical limits. The results from the classification and regression trees analysis applied to the Slaughter Module confirmed that the process of chilling carcasses is a critical control point. The method identified a cutoff value of a 2.2-log increase in the number of organisms during chilling as a critical value above which high levels of contamination would be expected. When classification and regression trees analysis was applied to the cooking effects part of the Preparation Module, cooking temperature was found to be the most sensitive input, with precooking treatment (i.e., raw product storage conditions) ranked second in importance. This case study demonstrates the capabilities of classification and regression trees analysis as an alternative to other statistically based sensitivity analysis methods, and one that can readily address specific characteristics that are common in microbial food safety process risk models.

Effect of Cooking and Pre‐Cooking on Cell‐Wall Chemistry in Relation to Firmness of Carrot Tissues

The aim of this work was to investigate heat-induced changes in cell wall polysaccharides of carrot in relation to texture. Discs of fresh carrot (Daucus carota cv Amstrong) tissue were subjected to cooking (100°C, 20 min), with or without a pre-cooking treatment (50°C, 30 min). Alcohol-insoluble residues were prepared from the tissues and were extracted sequentially with water, NaCl, CDTA, Na2CO3 and 0·5 M KOH to leave a residue. These were analysed for their carbohydrate compositions, their degree of methyl esterification and the molecular size of selected soluble polysaccharides. Cooking caused tissues to soften. This involved cell separation, an increase in water- and salt-soluble, high-molecular-weight pectic polysaccharides and a concomitant decrease in the pectic polymers in all wall extracts and the residue. Pre-cooking prior to cooking enhanced cell–cell adhesion and reduced the extent of softening. This was accompanied by a general reduction in the degree of methylesterification of cell-wall pectic polymers, and a decrease in the cooking-induced modification to all pectic fractions. The firming effect of pre-cooking could be reversed by extracting the precooked+cooked tissue with CDTA, a chelating agent. The role of Ca2+ cross-linked polymers and pre-cooking in the enhancement of firmness are discussed. © 1997 SCI.

Effect of Cooking and Pre-Cooking on Cell-Wall Chemistry in Relation to Firmness of Carrot Tissues

The aim of this work was to investigate heat-induced changes in cell wall polysaccharides of carrot in relation to texture. Discs of fresh carrot (Daucus carota cv Amstrong) tissue were subjected to cooking (100°C, 20 min), with or without a pre-cooking treatment (50°C, 30 min). Alcohol-insoluble residues were prepared from the tissues and were extracted sequentially with water, NaCl, CDTA, Na2CO3 and 0·5 M KOH to leave a residue. These were analysed for their carbohydrate compositions, their degree of methyl esterification and the molecular size of selected soluble polysaccharides. Cooking caused tissues to soften. This involved cell separation, an increase in water- and salt-soluble, high-molecular-weight pectic polysaccharides and a concomitant decrease in the pectic polymers in all wall extracts and the residue. Pre-cooking prior to cooking enhanced cell–cell adhesion and reduced the extent of softening. This was accompanied by a general reduction in the degree of methylesterification of cell-wall pectic polymers, and a decrease in the cooking-induced modification to all pectic fractions. The firming effect of pre-cooking could be reversed by extracting the precooked+cooked tissue with CDTA, a chelating agent. The role of Ca2+ cross-linked polymers and pre-cooking in the enhancement of firmness are discussed. © 1997 SCI.

Relationships between the textural changes and the contents of calcium, magnesium ions, and non-freezing water in the alcohol-insoluble solids of snap bean pods during cooking processes

The alcohol-insoluble solids (AIS) of snap bean ( Phaseolus vulgaris L.) pods after different cooking treatments were used as testing materials. The contents of calcium, magnesium ions and non-freezing water, which were analysed by differential scanning calorimetry, in the AIS were determined and compared with the firmness of the bean pod tissues after different cooking treatments. It was observed that the contents of calcium and magnesium ions in the AIS of the bean pods after direct cooking were lower than those of fresh and precooked bean pods, and were also lower than those of the bean pods after precooking followed by cooking. The contents of these metal ions were significantly and positively correlated to the tissue firmness ( P < 0.01). The degree of esterification (DE) of pectin in the tissue after precooking was 39.3%. The DE of of pectin in the tissue after precooking followed by cooking was 39.9%. These DE values were significantly lower ( P < 0.05) than that in the fresh tissue (46.0%) or that in the tissue after direct cooking (46.0%). Moreover, the amounts of non-freezing water in the AIS of fresh and precooked bean pods were larger than those of the bean pods after precooking followed by cooking and direct cooking. This also showed a significant and positive correlation to the tissue firmness ( P < 0.05). It was apparent that the linkages between the pectin molecules in the tissues of snap bean pods after precooking were changed. This change was caused by the action of pectinesterase in de-esterification of pectin molecules and subsequent formation of calcium or magnesium bridges between the free carboxyl groups of adjacent pectin molecules, which resulted in increases in the amounts of nonfreezing water in the AIS and in the tissue firmness. These results can be taken as further supporting evidence for the theory of the firming effect of precooking treatment of vegetables.

Microwave Versus Water-Bath Precooking of Turkey Rolls

Fifteen Broad Breasted Large White turkeys, 22 weeks of age, were slaughtered in each of three trials. Each turkey was hand-deboned and formed into two skin-encased rolls. One roll from each bird was precooked electronically while the other was precooked in a water bath. After a three-week period of frozen storage, the rolls were final-cooked in a conventional electric oven. Three rolls from each precooking treatment were subjected to core sampling after preparation, after precooking and after final cooking and analyzed for total aerobes and coliforms. Random sairlples were taken from each of the other 12 rolls in each treatment as bite-sized pieces of meat and presented to a group of experienced taste panelists for evaluation of flavor, tenderness and juiciness. Duplicate shear force values were obtained for light and dark meat from each of the rolls. All 12 rolls in each precooking treatment were weighed before and after cooking to determine yield.Yield was significantly greater from rolls precooked electronically. The panelists were unable to observe a significant difference in flavor or tenderness of the rolls due to the precooking treatments. Shear force values for rolls, precooked by either method, were not significantly different. The panelists rated microwave precooked samples significantly more juicy than water-bath precooked samples. There was no apparent difference in the effectiveness of either precooking method in reducing microbial populations.