Heat Penetration Characteristics Research Articles

Effects of different types of starches on heat penetration and physicochemical characteristics in alfredo sauce

Corn starch is frequently used as a thickening agent in food products because of its stability under thermal processing conditions. However, with fluctuating raw material costs due to weather conditions, disruptions in supply chains, and geopolitical challenges, there is an increasing need to explore alternative sources of starch. This study examines the effect of retort processing on the heat penetration and physicochemical aspects of modified corn, tapioca, and potato starches in Alfredo sauce. Modified corn starch, commonly used in commercial sauces, was compared with tapioca and potato starches to evaluate their effects on viscosity, color, and processing times required to achieve a F0 = 6 for Clostridium botulinum. Using the reference starch concentration of 1.90%, modified corn starch showed a significant increase in viscosity from 3,328 cP to 13,296 cP with a processing time of 31.33 min. Modified tapioca starch, at the same concentration, increased from 3440 cP to 8176 cP over 38.38 min, indicating superior thermal stability being the longest cooking time evaluated between all samples. For modified potato starch, using the reference concentration, viscosity increased from 1,200 cP to 4,656 cP, with a processing time of 31.93 min. Adjusting the starch concentration to 3% for modified tapioca starch and 2.38% for modified potato starch increased viscosity to 14,400 cP and 16,336 cP, respectively. These adjustments resulted in a darker Alfredo sauce, with the L value decreasing from 92.27 to 83.67 due to the longer cooking time. Heat penetration findings suggest that modified potato starch can replace modified corn starch safely using the reference concentration (1.90%) without altering the process holding time but requiring further adjustments to match commercial viscosity standards, while modified tapioca starch, although requiring higher concentrations and longer processing times, was tested for retention time at 3.00% and to be a feasible alternative. This study offers valuable insights to the food industry in selecting appropriate starches to maintain the quality and safety of thermally processed Alfredo sauce.

The Effects of Effective Thermal Conductivity of Porous Materials Under Vapor Flow in Sudden Enlargement-Contraction Channel on Local Heat Transfer

This study aims to obtain the local heat penetration and local heat convection characteristics in a system where a flow of heated vapour cedes thermal energy to a horizontal heat-sink plate. The heat penetrates a bed of porous materials with varia

Development, Physiochemical characterization and Histopathological studies of Pasteurized Bilimbi (Averrhoa bilimbi L.) Syrup

Averrhoa bilimbi commonly known as bilimbi, is starchy and nutritious fruit rich in ascorbic acid and minerals. The study was aimed for the development of pasteurized bilimbi syrup, a value added and shelf stable product from bilimbi and thereby increase its market value. The heat penetration characteristics during pasteurization of the syrup packed in polypropylene bottles were studied. 29% of bilimbi syrup diluted using potable water to a concentration of 21ºBrix was selected by the sensory panel to serve as ready to drink after dilution. Animal studies to detect histological changes in cardiac, renal and hepatic tissues of experimental rats fed with bilimbi syrup did not show any changes in morphology. Shelf life of the product at ambient conditions (25 to 28ºC) was determined by analyzing the physiochemical changes in the product during storage for a period of 10 months. pH increased from 3.23 to 3.75, titratable acidity decreased from 2.54 to 1.07% of oxalic acid, total sugar increased from 59.59 to 65.07g/100g and ascorbic acid decreased from 44.61 to 34.25mg/100g on the eleventh month. The color of the product showed a rapid change affecting the L* value which decreased from 49.19 to 28.25. The sensory acceptability of the product also decreased which was below the acceptable level on the 11th month. Hence shelf life of pasteurized bilimbi syrup was estimated as ten months at ambient conditions.

Process Optimization for the Development of Shelf Stable Ready to Eat Tomato Curry in See through Retort Pouch

Ready to eat tomato curry in see through retort pouches was developed using steam air retort. The product was found to be commercially sterile after retorting to an F0 value of 7.34 minutes. The heat penetration characteristics of the product was studied and revealed a total process time of 30.38 minutes to attain the above F0 value and the cook value was 66.03 minutes. The characteristics of the see through retort pouch used for the study was analysed and our results showed that it had good barrier properties and is suitable for food contact applications. Tomato is known as a rich source of lycopene, thus in this study the ready to eat tomato curry was also analysed to determine the changes that occurred in the lycopene content during processing. Shelf life studies conducted revealed a shelf life of one year at ambient temperature (26 to 28°C).

A Case-study: Temperature Distribution and Heat Penetration in Steam-air Retort, Using Glass Jars and Retort Pouches

Abstract Retort thermal sterilization of canned food is a technology, which allows preserving food products by applying heat on packaged food in retorts (autoclaves) at temperatures up to 121 °C. The thermodynamics of the processes in the retort are influenced by the product stacking method in the basket and packaging material. The aims of this study were: 1) to analyse and compare temperature distribution (TD) and the slowest to heat location in the steam-air retort stacked with glass jars and with retort pouches; 2) to analyse and compare commercial product heat penetration (HP) characteristics in glass jars and retort pouches. Temperature measurements were performed with wireless thermocouples. The come-up time (heating phase) required to achieve in the retort temperature uniformity criteria of ±0.5 °C, is 28 min when the retort is stacked with glass jars, and 24 min when the retort is stacked with retort pouches. Total calculated process time (holding phase), necessary to achieve the sterilization value (F0 of 3 min), for sample in glass jars was 67 min, but in retort pouches – 62 min. The overall sterilization process time difference between two considered packaging types was 9 min, which is significant amount of time in the context of commercial processing. The study clearly shows the necessity to perform the Temperature Distribution and Heat Penetration study, as each packaging material, stacking method and product will affect sterilization process thermodynamics and, therefore, the overall process time and consequently - the safety of food product.

Heat penetration characteristics and quality of ready‐to‐eat shrimp in masala ( Litopenaeus vannamei ) in flexible retortable pouches

Shrimp in masala is a famous south Indian dish prepared using white leg shrimp (Litopenaeus vannamei) in the culinary style. The present investigation was aimed to optimize different F0 values of the shrimp in masala packed in flexible retortable pouches. The product was thermally processed at different lethality and heat penetration characteristics indicating similar heating and cooling lag factor. Fh value was 24.5 and 23 min for the product processed at Fo values of 8 and 9 min, respectively. Total processing time was 37.11 and 39.88 min, respectively, for Fo 8 and 9 min. Cook value of the processed product was 84.07 min for Fo 8 min and 92.41 min for Fo 9 min. Except cohesiveness, all other instrumental texture parameters showed significant differences (p < .05) between the two samples. Based on the organoleptic evaluation, product processed at Fo 8 min was rated better. Practical applications Shrimps are regarded as one of the delicacy food items across the globe and hence has great demand. Currently, Pacific white leg shrimp is the most widely cultured shrimp variety. Shrimp in masala, an ethnic dish is very popular among Asians and elsewhere. However, due to its limited shelf life and preparation time, its consumption is limited only during special occasions. The present study optimizes the thermal process conditions to develop ready-to-eat Shrimp masala, which can be kept at ambient temperature for prolonged duration which can be made available to consumers year-round. Apart from this, during the period of glut production, this highly efficient and economical technology can be used for preserving shrimps in RTE form.

Thermal Process Evaluation of Analogue Shrimp Product (ASP) from Lizard Fish (Saurida tumbil) in Retort Pouches

Background: Seafood analogue is a ready to make value added product prepared out of surimi. Thermal processing of restructured products in retort pouches such as fish ball in curry medium, surimi stew in white tripod, boneless rohu balls in curry. Also no work had done on thermal processing of shrimp analogue products in retort pouches. The main objective of this work was to develop the analogue shrimp product from lizardfish and to compare the heat penetration attributes of analogue shrimp curry and masala using retort pouches and different sterilization methods such as steam / air over pressure retort and water immersion retort.Methods: Analogue shrimp products were prepared and thermally processed in retortable pouches. About 125g of shrimp analogue product and 100g of curry (masala) were filled in retort pouches of size, 150x200mm. Air inside the pouch was exhausted by steam injection followed by heat sealing and processing at 121.1°C in a retort by steam/air over pressure retort and water immersion retort. The difference in the heat penetration characteristics of analogue shrimp products processed in retort by steam/air over pressure retort and water immersion retort were studied. Result: The results showed that minimum heating lag factor and minimum come up time led to faster heating rate which decreased total process time in imitated shrimp curry by steam/ air retort. At the same time the cook value was low in curry medium processed by steam air retort. So finally conclude that imitated shrimp curry processed by steam air retort was good.

Ready to Eat Cassava (Manihot esculenta crantz) in See Through Retort Pouch and Its Storage Stability

Thermal processing of cassava packed in see through retort pouch (polyester coated with Silicon dioxide/nylon/cast polypropylene) was done using still water spray retort. Heat penetration characteristics were studied and shelf life was determined. Earlier studies were conducted for developing ready to eat cassava in brine, packed in High Impact Poly Propylene trays and thermally processed. The results revealed the leaching of amylose from cassava into the brine that lead to formation of turbidity in brine and made the product soft and thereby unacceptable. The product had a shelf life of only 75 days. The present study aimed to improve the shelf life of the product by thermally processing cassava as a solid pack with curcumin added to it to provide a colour that is stable even after thermal processing. Cassava vacuum packed in see through retort pouches were thermally processed at 121.1 °C to an F0 value of 8.97 min. The product stored at ambient temperature (28 ± 2 °C) was found to have a shelf life of 12 months.

English

Effect of retort (thermal) processing on the shelf life and safety of ethnic Indian food products namely egg curry and egg burji were investigated. Ready-to-eat egg products were packed in four layer laminated retort pouches and processed in a steam-air retort with overriding pressure. Time-temperature profile of thermal processing was determined and the same was used for heat penetration characteristics. The thermal processing parameters like retort temperature, heating lag factor (Jh), heating rate index (fh), process time (B), F0 value and cook value (Cg) were determined. The retort processed egg products were analysed for microbiological sensory and chemical characteristics under ambient (27-30°C) and accelerated temperature (45°C) for a period of 12 months. Microbiological analysis indicated that retort processing has significantly reduced the microbial loads (P E‚ 0.05). The changes in chemical characteristics and sensory quality on storage were insignificant. Microbiological analysis revealed that product was commercially sterile and fit for consumption. The samples were rated excellent by the taste panel and remained in good condition even after 12 months of storage under ambient conditions. Key words: Retort processing, egg curry, egg burji, free fatty acid, peroxide value and cook value.

The study of heat penetration of kimchi soup on stationary and rotary retorts.

The aim of this study was to determine the heat-penetration characteristics using stationary and rotary retorts to manufacture Kimchi soup. Both heat-penetration tests and computer simulation based on mathematical modeling were performed. The sterility was measured at five different positions in the pouch. The results revealed only a small deviation of F0 among the different positions, and the rate of heat transfer was increased by rotation of the retort. The thermal processing of retort-pouched Kimchi soup was analyzed mathematically using a finite-element model, and optimum models for predicting the time course of the temperature and F0 were developed. The mathematical models could accurately predict the actual heat penetration of retort-pouched Kimchi soup. The average deviation of the temperature between the experimental and mathematical predicted model was 2.46% (R2=0.975). The changes in nodal temperature and F0 caused by microbial inactivation in the finite-element model predicted using the NISA program were very similar to that of the experimental data of for the retorted Kimchi soup during sterilization with rotary retorts. The correlation coefficient between the simulation using the NISA program and the experimental data was very high, at 99%.

Effect of thermal processing on the biochemical constituents of green mussel (Perna viridis) in Tin-free-steel cans.

The effect of thermal processing on the biochemical constituents of green mussel (Pernaviridis) in brine was investigated. Depurated mussel samples were thermal processed in tin-free steel cans (TFS) at F0 8.43. The time temperature data was collected during heat processing using EVAL data recorder and heat penetration characteristics were determined using formula method. The total process time was 27.48min and the processed cans were found to be commercially sterile. The mineral composition of processed mussel was significantly higher than raw samples. The instrumental texture analysis indicated that product become soft after thermal processing.The thermal process led to a significant decrease in total amino acid and fatty acid content of the samples. Even though the samples showed a decrease in amino acid and fatty acid composition after thermal processing, the mussel meat was nutritionally well balanced with respect to essential anino acids and fatty acids.Hence the product can be considered as a food source with high quality protein and fat to fulfil consumer's requirements.Based on sensory analysis, the processed products were found acceptable during the study period.

Determination of Optimum Sterilization Condition for the Production of Retorted Kimchi Soup

In order to optimize process conditions for manufacturing retorted Kimchi soup by using stationary and rotary types systems were applied for sterilization process. For investigating the differences in heat penetration characteristics during sterilization, Kimchi soup was packed into retort pouches, and sterility (F? value) at various positions in the product was measured through a wireless F? sensor. Heat penetration characteristics were significantly affected by sterilization method. From data analysis, optimum ranges of sterilization temperature and time was determined to be 120.7℃, 13 min for rotary type and 120.7℃, 20 min for stationary type. At those conditions, they had similar sterility (F? value). The results showed that rotation provides faster heat penetration and more uniform sterility than various positions of the product. These results derived a lot of advantages from related industry. For instance, many of the more viscous semi-liquid products and heat sensitive natural products could be sterilized in the lager pouch sizes without overcooking or scorching. Hence, current study suggests that rotary type retort would make it possible not only to reduce processing times as 35～45%, but also to improve the quality of product as overall taste, flavor, color, and texture with significant difference (p< 0.05).

Effect of Thermal Sterilization on the Selected Quality Attributes of Sweet and Sour Carp

In this study, a traditional Chinese dish, a ready-to-eat sweet and sour carp was developed. The effects of sterilization temperature (110, 115, 121, and 130°C) on the selected properties, including heat penetration characteristics, as well as rheological, instrumental color, texture, and sensory attributes, were investigated at the same lethality value (F0) of 4.5 min. The results showed that the heat penetration parameters of cooking value (C-value) and the ratio of C-value to F0 value (C-value/F0) exhibited an inverse relationship with processing temperature. The color and rheological properties of the sauce and the texture of the fish sterilized at 130°C were better preserved compared to those sterilized at other temperatures. The sensory attributes of the product sterilized at 130°C scored highest among the final products sterilized at the four temperatures. This study suggested that short-time sterilization at a high temperature can minimize the negative thermal impact on sweet and sour carp product, which would be feasible in the practical production.

Effect of filling ingredient on the quality of canned yellowfin tuna (Thunnus albacares)

SummaryIn this study, the effect of different vegetables baby corn, green pea, broccoli as filling ingredients along with yellowfin tuna (Thunnus albacares) on the heat penetration characteristics and quality changes were assessed. Heating and cooling lag factors (Jh and Jc) were least for tuna with broccoli and tuna without vegetables, respectively. Heating rate index was in the range of 13.5–19.3 min with least value for tuna with broccoli. Heat processing increased the hardness and chewiness of tuna significantly (P &lt; 0.05), whereas cohesiveness decreased. Thermal processing resulted in higher L*and hue (h) value for tuna. Substantial decrease in a* value was observed for tuna with broccoli and peas where as b* value showed an increase for tuna with baby corn. Tuna packed with green pea and baby corn was rated better sensorily, whereas tuna with broccoli was rated least.

Large eddy simulation of turbulence in ocean surface boundary layer at Zhangzi Island offshore

This study uses a large eddy simulation (LES) model to investigate the turbulence processes in the ocean surface boundary layer at Zhangzi Island offshore. Field measurements at Zhangzi Island (39 degrees N, 122 degrees E) during July 2009 are used to drive the LES model. The LES results capture a clear diurnal cycle in the oceanic turbulence boundary layer. The process of the heat penetration and heat distribution characteristics are analyzed through the heat flux results from the LES and their differences between two diurnal cycles are discussed as well. Energy balance and other dynamics are investigated which show that the tide-induced shear production is the main source of the turbulence energy that balanced dissipation. Momentum flux near the surface shows better agreement with atmospheric data computed by the eddy correlation method than those computed by bulk formula.

Heat penetration characteristics and physico-chemical properties of in-pouch processed dairy dessert (kheer).

Kheer, a traditional milk product of South East Asia, containing cooked rice grains in a creamy sweetened concentrated milk, has no large-scale production due to its poor shelf life. Shelf-life was improved by development of a process based on in-pouch thermal processing employing a rotary retort. Product development included optimization of rice-to-milk solids ratio (0.18-0.52) and total milk solids levels (16-26%) to simulate the conventional product in taste, appearance and textural attributes. Various Fo values (12.4-14.8) were examined with regard to product quality. While the TBA value tended to increase (0.073-0.081) the reflectance value (35.3-43.4) declined with increasing Fo. The pH of the product (6.04-6.10) showed a slight tendency to increase with Fo. Sensorily, the product was found to be acceptable for a period of 150days at 37°C.

INVESTIGATION OF SHELF LIFE AND HEAT PENETRATION ATTRIBUTES OF READY-TO-EAT “FISH PEERA” FROM ANCHOVY (STOLEPHOROUS COMMERSONI) IN RETORT POUCHES

Fish peera, a traditional product from anchovies, was prepared and processed at 121.1C for 38 min in an over pressure autoclave in indigenously developed retort pouches having a three-layer configuration of 12.5 µm polyester/12.5 µm aluminum foil/80 µm cast polypropylene of size 11 cm × 17 cm. Heat penetration characteristics of the product were studied using Ellab CTF 9008 (Ellab A/S, Roedovre, Denmark), Fo cum cook value integrator. Fish peera was processed to a Fo value of 7 and cook value of 66.02 min. Storage studies with reference to sensory, biochemical and microbiological parameters indicated that the product had a shelf life of 1 year when stored at ambient temperature (28 ± 2C). PRACTICAL APPLICATIONS The demand for ready-to-eat fish products is increasing both in domestic and international market because of health benefits associated with fish and fishery products. Fish products thermally processed in retortable pouches offer several advantages. Apart from being less expensive, these products can be stored at ambient temperature for more than 12 months without any refrigeration. Many varieties of fish products, especially traditional and ethnic products are having great demand. Fish peera, a traditional dish of Kerala prepared using anchovies, have limited storage life at room temperature as the product becomes rancid due to coconut. This products can be kept for a period of 1 year at ambient temperature (28 ± 2C) when subjected to thermal processing at 121.1C for 38 min to a Fo value of 7 and cook value of 66 min in an over pressure autoclave in indigenously developed retort pouch.

HEAT PENETRATION CHARACTERISTICS AND QUALITY CHANGES OF INDIAN MACKEREL (RASTRELLIGER KANAGURTA) CANNED IN BRINE AT DIFFERENT RETORT TEMPERATURES

ABSTRACT Indian mackerel (Rastrelliger kanagurta) was processed in brine in indigenous polymer‐coated tin‐free steel cans to a common lethality value of 8 min at three different retort temperatures, namely 115, 121 and 130C. All the three batches were found to be commercially sterile upon testing using sodium thioglycollate broth. The heat penetration parameters were found to be significantly influenced by the retort temperature. The lag factor of heating (jh value) decreased, whereas the lag factor of cooling (jc value) increased with increase of retort temperature (P &lt; 0.05). The heating rate index (fh value) showed a decreasing trend with increase of retort temperature. The total process time (TPT) taken to attain the targeted lethality decreased with increase in retort temperature. At 115, 121 and 130C, the targeted lethality value could be attained in 60, 33 and 15 min, respectively. Thermal processing mackerel at 121 and 130C helped in reducing the TPT by 45 and 75% as compared to those processed at 115C. Cook value (CV) maintained an inverse relationship with retort temperature. At 121 and 130C, the CV recorded was 36 and 55% lower than at 115C. CV to F0value ratios at 115, 121 and 130C were 15.25, 9.75 and 6.88, respectively. Mackerel samples processed at three retort temperatures were analyzed for their sensory qualities employing subjective and objective methods. Statistical analysis indicated the significance of retort temperature on the color and texture profile attributes, and the sensoryqualities of mackerel (P &lt; 0.05). Analysis of Commission Internationale d’Eclairage lab values show that the L*value increased, while the a*value decreased with increase of retort temperature. The b*value did not show much difference with retort temperature. Instrumental analysis of texture showed that texture profile attributes and Warner–Bratzler shear force of mackerel muscle reduced with precooking and subsequent thermal processing. Among the thermally processed samples, better textural attributes were associated with samples processed at higher temperature. Sensory analysis revealed that all the sensory attributes except flavor are significantly affected by the retort temperature (P &lt; 0.05).PRACTICAL APPLICATIONSThis work describes the effect of three different retort temperatures on heat penetration characteristics, instrumental color, texture and sensory attributes of mackerel canned in brine to a common lethality value. The study indicates that processing at higher temperature helps in reducing the duration of exposure of the product to heat treatment, which ultimately yielded a product with better color, texture and sensory attributes in comparison to products processed at lower temperatures. The reduction in processing time has its implications on the economics of production in case of commercial operation.

HEAT PENETRATION CHARACTERISTICS OF SMOKED TUNA IN OIL AND BRINE IN RETORT POUCHES AT DIFFERENT ROTATIONAL SPEEDS

ABSTRACT Yellowfin tuna (Thunnus albacares) steaks were light smoked using coconut husks and packed in indigenously developed retort pouches of size 17 cm × 11 cm, having a configuration of 12.5-µm polyester/12.5-µm aluminum foil/80-µm cast polypropylene. Hot refined sunflower oil and 2% brine solution were used as the filling medium. Processing was done to an Fo value of 10 in an overpressure autoclave with a facility for rotation. Heat penetration characteristics of the product were studied using an Ellab CTF 9008, an Fo-cum-cook value integrator. Different batches of tuna were processed in oil and brine media to an Fo value of 10 at 2, 4, 6 and 8 rpm, and compared the results with that obtained from a stationary retort. Increase in speed of rotation gave a reduction in total process time and a lower cook value. Heat penetration was lowest for the stationary retort and increased with the speed of rotation in both the oil and brine media. Heat penetration was faster in the brine medium for the same rotation speed and stationary retort when compared with that in the oil medium. PRACTICAL APPLICATIONS The study shows that heat penetration was faster in brine- than in oil-packed tuna because of the higher viscosity of the oil, which prevents rapid convection movement within the pouches. Because the retort pouch has a thinner profile than cans, heat penetration is faster during rotation, heat-induced Maillard reaction will be less, and the product will have better sensory attributes and nutritional properties. By rotation, the process time can be reduced, which can save time, fuel and energy and also obtain products with better nutritional value, color, taste and flavor.

Heat penetration characteristics of mushroom curry packed in retort pouch

White button mushrooms (Agaricus bisporus) in curry, packed in retort pouches were heat-processed in a pressurised autoclave. Retort pouches (105 µ thick) used had an outer polyester layer (12.5 μ), a middle aluminum layer (12.5 µ) and an inner cast polypropylene layer (80 µ); size 20 cm×16 cm; seal size 10 mm and lip size 4 mm. Adequate number of pouches were fixed with glands to insert the thermocouples for recording core temperature of mushrooms using data recorder and computer connected to each other. The mushroom curry was heat-processed to F0 value of 10.3 (time in minutes at 121°C) and heat penetration parameters were calculated. The heating curve obtained was logarithmic in nature and the processed mushrooms were free of bacterial contamination and had desirable sensory attributes. The pouches withstood the pressure and temperature of the retort without delaminating, shrinking or wrinkling and the curried mushroom was found to be sterile over a one year storage period.