Cook Value Research Articles

Food Quality Evaluation using Model Foods: a Comparison Study between Microwave-Assisted and Conventional Thermal Pasteurization Processes

Thermal process optimization has focused on traditional sterilization, with limited research on pasteurization or microwave-assisted thermal processing. Model foods have been developed as quality evaluation tools for thermal pasteurization processes, but there are no comprehensive studies demonstrating how these model foods could be used to evaluate and compare the resulting food quality after different pasteurization processes. The aim of this study was to develop a methodology using image and quantitative analyses for quality evaluation of pre-packaged food pasteurized using a microwave-assisted pasteurization system (MAPS) and traditional hot water method. Four pasteurization processes (MAPS and hot water method at 90 and 95 °C) were designed to have an equivalent accumulated thermal lethality at the cold spot of at least 90 °C for 10 min to control nonproteolytic Clostridium botulinum spores. Color-based time-temperature indicators in mashed potato and green pea model foods were quantified using image analysis. Results showed that median color values were useful in assessing overall color change, and interquartile range was an indicator of burnt areas. MAPS 95 °C was the best process because it had the smallest hot spot cook values and the least color change, while the 90 °C hot water process was the worst. Model foods and image analysis techniques were useful pasteurization process quality evaluation tools and made it possible to visualize the potential food quality change volumetrically, throughout a food package. In the future, these tools could be combined with computer simulations to optimize the quality of pilot-scale and industrial MAPS or conventional pasteurization processes.

Textural and sensory characteristics of retort-processed freshwater prawn (Macrobrachium rosenbergii) in curry medium

ABSTRACTFreshwater prawn in curry was thermally processed to three F0 values of 6, 8, and 9 at 116°C. Total process times for F0 values of 6, 8, and 9 were 53, 57, and 63 min, respectively. The cook value (CV) obtained at F0 values of 6, 8, and 9 was 87.53, 107.93, and 117.55 min, respectively. Instrumental texture profile analysis revealed that except springiness, the values of hardness, gumminess, and chewiness decreased as the F0 values increased. CIELAB values of L*, b*, and a* increased as the F0 values were increased. The organoleptic evaluation scored the highest for the product processed to F0 7 min.

Microwave pasteurization of pre-packaged carrots

This research investigated the application of 915 MHz microwaves in pasteurizing pre-packaged vegetables. A specially designed 915 MHz single-mode microwave-assisted pasteurization (MAP) system was used to process carrot cuboids in brine pre-packaged in 8-oz polymer pouches. Gellan gel was formulated and selected as the model food to simulate the real foods processed by the MAP system; heating patterns and cold spots of the pouched samples were detected by a chemical-marker based computer vision method. Two MAP processes (F90°C = 3 min and F90°C = 10 min) targeting Clostridium botulinum type E spores were developed and compared with conventional hot water (HW) processes resulting in equivalent microbial safety. Compared with an equivalent HW process, MAP process greatly reduced the total processing time, reduced the cook values and improved quality uniformity of the products. Quality evaluation showed the impacts of MAP processing on each quality attribute of carrot products depended on the specific quality parameter selected.

Sous Vide Processing as an Alternative to Common Cooking Treatments: Impact on the Starch Profile, Color, and Shear Force of Potato (Solanum tuberosum L.)

This study aimed to assess the effect of sous vide cooking on the total and resistant starch content, color, and shear force in three potato cultivars (Agria, Agata, and Carrera). Potato strips were also cooked by three common treatments (boiling, frying, and microwaving) to evaluate the differences between the methods. According to principal component analysis (PCA), sous vide-processed cv. Agria and Agata potato strips were grouped with boiled samples, in contrast, cv. Carrera sous vide samples were grouped with microwaved samples. Higher water losses were associated with microwaved potatoes due to the diffusion of water inside the tuber. In addition, a significant decrease in shear force was obtained after microwaving and sous vide cooking (p < 0.05) irrespective of the treatment strength. The three cultivars became less bright, and the intensity of the color decreased; however, variations in the cook value (C100, min) between treatments did not affect the lightness and hue angle. Regardless of the initial value of resistant starch and the intensity of the cooking process, all of the cultivars reached a final content of less than 5%. From our results, in-pack sterilization may be considered for application in the food industry as a technology that has a similar impact to conventional cooking treatments used on potato products.

Kinetics of color development of peanuts during dry roasting using a batch roaster

AbstractThe kinetics of color development during peanut roasting were investigated at roasting temperatures from 149 to 204°C which produced Hunter L color values of 25–65. Preliminary and equivalent roasting trials were conducted using a batch roaster simulating the parameters of an industrial continuous belt roaster. Hunter L and b values of the roasted peanuts were fitted well to first‐order models (mean R2 &gt; 0.93). The activation energy calculated from the first‐order model of the L and b values ranged from 1.0 to 1.1 × 108 J/kg mol. High‐temperature roasting decreased the uniformity of color development from seed to seed and throughout of the kernel. A zc value of 37.6°C was calculated using the first‐order model of the L values. The cook values were 11.5–23.6, 24.5–31.6, and 41.5–57.5 min for light, medium, and dark roasting, respectively.

Development of model food systems for thermal pasteurization applications based on Maillard reaction products

Model food systems with Maillard reaction products have been an effective tool to assess process lethality for microwave-assisted thermal sterilization. However, model food systems used for sterilization temperatures (110–130 °C) are not optimal for pasteurization temperatures (70–100 °C). The purpose of this research was to develop and assess model food systems to quantify process lethality and food quality for pasteurization applications, such as microwave-assisted pasteurization. Chemical marker M-2 (4-hydroxy-5-methyl-3(2H)-furanone) and color reaction kinetics were determined for egg white, mashed potato, and gellan model foods. M-2, L*, and a* value changes followed first order reaction kinetics and were significantly correlated to thermal lethality and cook value. Mashed potato was the optimal model food, in part because it had the greatest range of L* and a* reaction rates at 90 °C. Mashed potato model foods developed in this study could be used in the future to describe safety and quality reactions during pasteurization process evaluation.

Evaluation of Textural Quality as a Parameter to Optimize Thermal Process During Retort Pouch Processing of Boneless Rohu Balls in Curry Medium

Boneless fish ball from Rohu fish (Labeo rohita) in gravy packed in four-layered laminated retort pouch was processed in a steam/air mixture over-pressure retort at 121.1C to three different F0 values of 6, 7 and 9 min. Time-temperature data were collected during heat processing using an Ellab Sterilization Monitoring System. Texture profiles such as hardness, springiness, gumminess and chewiness decreased as the F0 value increased. Highest cohesiveness coincided with the highest score of texture. The L* values decreased whereas a* and b* values increased with increasing F0 values. Based on the commercial sterility, sensory evaluation, color and texture profile analysis F0 value of 7 min and cook value of 67.48 min, with a total process time of 42.21 min at 121.1C was found satisfactory for the development of retort pouch processed “Rohu ball” in curry. Practical Application Fish ball is a value added food product convenient to prepare and consume and thus suitable for the changed lifestyle of urbanized people. The boneless fish ball from Rohu fish is an improvisation of use of freshwater fishes where their small bone contents restrict use to a greater extent. Incorporation of fish ball in curry will add to a new dimension toward value addition of freshwater fish particularly in North-east region. Fish ball in curry processed in retort pouch would add to a new appropriate channel to Supermarket chain.

Development of ready to drink calcium fortified shrimp soup in retortable pouches

The aim of the study was to develop ready to serve calcium fortified shrimp soup in retortable pouches. Shrimp soup was prepared from Indian white shrimp ( Fenneropenaeus indicus ) and thermal processed at 121, 115 and 110OC to an F0 value of 6. The calcium fortified soup was then compared with control samples. The effect of different process temperatures on quality was analysed. The samples processed at 110OC showed significantly higher (p≤0.05) cook value and 121.1 O C showed the least. All the pouches were found to be commercially sterile. The viscosity of soup was significantly higher (p≤0.05) in control packs compared to fortified soups. Significantly higher (p≤0.05) b* value was observed in fortified soup compared to control. Thermally processed calcium fortified shrimp soup was in acceptable condition during the storage period of 90 days at ambient temperature without any significant change in calcium content. Sensorily, the product processed at 121OC rated better compared to 115 and 110 O C.

Rapid (microwave) heating rate effects on texture, fat/water holding, and microstructure of cooked comminuted meat batters

Comminuted and gelled, fat-containing meat products such as frankfurters and luncheon meats are commercially processed by heating relatively slowly (for up to 2h or more) to an endpoint of about 70°C prior to cooling. This study compared such a slow, ramp heating regime (0.5°C/min), terminated at 70°C, to rapid, square-wave cooking (one step: rapid 100°C/min heating to 70°C endpoint, plus isothermal holding prior to cooling, or two-step: rapid heating to 50°C, holding, then rapid heating to 70°C plus holding prior to cooling) on meat batter gel properties (fracture and small strain rheology, microstructure, cook loss, and expressible water). The results indicated that a rapid cooking process, with its inherent advantages of reduced process time, lower equipment footprint, and more efficient use of energy, can produce a product nearly equivalent in textural properties and cook yield to one processed by traditional smokehouse cooking when the cook value of the processes is similar and an intermediate (near 50°C) holding step is included (two-step rapid heating). One-step rapid heating negatively affected gel structural homogeneity and water/fat holding properties of fat-containing gels.

Relationship between Oil Uptake and Moisture Loss during Deep Fat Frying of Deboned Chicken Breast Meat

The relationship between moisture loss and oil uptake at different combination of Frying Oil Temperatures (FOT) and time during deep-fat frying of chicken meat was investigated in this study. Chicken meat samples were diced and fried at different FOT (170°C, 180°C, and 190°C) in an industrial fryer for periods varying from 5 to 900 s. Fat analysis was accomplished in a soxhlet extraction apparatus with petroleum ether solvent. Prior to fat analysis samples were freeze dried and the moisture analysis was based on the standard AOAC standard method. The results show that a cook value of 415 s was found to give the most ideal sensory characteristics. The relationship between moisture loss and oil uptake during the initial phase of frying (°C and 190°C, respectively, and the rate (1.35 g/s) at FOT 170°C was significantly (P < 0.05) lower.

Processing of chopped mussel meat in retort pouch

Chopped mussel meat packaged in retort pouches was processed in a laboratory-scale water immersion retort, adapted for processing under overpressure conditions. Retort temperature effects on product yield and on cook value were evaluated by setting the F0 at 7 min. The effects of different pre-treatments (salting and marination) on the characteristics of mussels were evaluated after processing at retort temperature of 118 °C and during a whole year of storage at 25 °C. The salted samples showed better yield during storage, while no differences were found for the other physicochemical parameters.

Effects of Combined Ohmic–Infrared Cooking Treatment on Microbiological Inactivation of Meatballs

AbstractThe effectiveness of combined ohmic–infrared cooking system on the microbiological quality of meatballs was studied. In the first step, samples were precooked in an ohmic heater at 15.26 V/cm. In the second step, ohmically precooked samples were processed in the infrared heater for the final cooking purpose at different combinations of heat fluxes (3.7, 5.7, 8.5 kW/m2), application distances (10.5, 13.5, 16.5 cm) and application times (4, 8, 12 min). The effects of infrared process conditions on total mesophilic aerobic bacteria (TMAB) counts of meatball samples were investigated. TMAB counts of meatball samples were reduced, ranging between 1.96 and 4.50 logarithmic units, depending on infrared process conditions used. Mold and yeast, Staphylococcus aureus, Clostridium perfringens, Salmonella spp., Listeria monocytogenes and Escherichia coli O157:H7 were not detected in the treated meatball samples. The effects of different infrared cooking conditions both on cooking value and pasteurization value were also determined. These results demonstrate the considerable potential for the application of ohmic–infrared combination cooking process to the meatballs.Practical ApplicationsMeat is a nutritious substrate for the growth of microorganisms and is highly susceptible to spoilage. The raw meat contaminated with pathogenic microorganisms is one of the main sources of foodborne illness. During conventional cooking, the interior region may not heat sufficiently and pathogens could survive in the product, unless the meat products have been properly heat‐treated. Therefore, there is a potential need for alternative cooking technologies, which provide a valuable tool to reduce the risk of pathogen growth in the products while shortening the treatment time. In this study, the combination of ohmic and infrared heating technologies was used for cooking of the meatball.

Steam Assisted Hybrid Cooking Behavior of Semitendinosus Muscle: Heterocyclic Amines Formation, Soluble Protein Degradation, Fat Retention, Surface Color, and Cooking Value

Beef (Semitendinosus muscle) was cooked in natural convection, forced convection and steam assisted hybrid oven and saturated steam oven at different oven temperatures until the geometric center of samples reached different end temperatures. Heterocyclic amine (HCA) compounds formation, soluble protein degradation kinetics, cook value, changes in fat content, surface colour and overall acceptance of cooked beef were determined. Soluble protein degradation of beef was considered as first order reaction kinetics and the reaction rate constants, k, were determined in the range of 0.014-0.052 min−1. In steam assisted hybrid oven had higher reaction rate constants compared to that of the convection ovens. The effect of cooking temperature on soluble protein degradation for natural convection, forced convection and steam assisted hybrid oven followed the Arrhenius type of equation with activation energies of 12.45, 14.57 and 60.16 kJ/mol, respectively. Lower HCAs contents, shorter cooking times, lower cook values and lower fat retention were obtained by steam assisted hybrid oven cooking. Steam assisted hybrid cooking could be considered as an alternative cooking method to obtain a healthier product without compromising the eating habits of conventional methods due to better appearance (moderate burned surface) than saturated steam oven samples and a product retaining the most of the nutritional values.

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.

Agency-Based Empowerment Training Enhances Sales Capacity of Female Energy Entrepreneurs in Kenya

Globally, women's involvement in clean cooking value chains has been minimal. This is partly because of the multiple challenges faced by women that impede their capacity to effectively engage in the energy sector. To better discern gender-specific differences in involvement in the energy sector, the authors conducted a randomized trial in Kenya to compare sales performance of newly trained male and female improved cookstove entrepreneurs and to test the effects of an agency-based empowerment training on business activity. A total of 257 entrepreneurs completed either a 4-day entrepreneurial training (control) or a 4-day empowerment training (intervention) and were followed for nearly 8 months documenting business activity and sales. The empowerment training led to more than doubling of sales for both genders. In addition, participants in the intervention group were significantly more likely to demonstrate business commitment over time and nearly three times more likely to be higher sellers (relative risk = 2.7, 95% CI [1.4, 5.4]), controlling for gender and rural/urban locale. Women outsold men by a margin of nearly 3 to 1 and were more likely to continue to pursue leads despite limited sales. Nonactive participants (those selling 1 improved cookstove or less) were a larger percentage of the control group (72%) than the intervention group (50%), and more men were nonactive participants (65% of men) compared with women (56% of women).These data show that women can serve as active improved cookstove entrepreneurs in both urban and rural settings and that targeted agency-based empowerment training can significantly increase women's capacity to engage effectively within the improved cookstove value chain.

Use of Behavior Change Techniques in Clean Cooking Interventions: A Review of the Evidence and Scorecard of Effectiveness

Despite decades of effort, around 2.8 billion people still rely on solid fuels to meet domestic energy needs. There is robust evidence this causes premature death and chronic disease, as well as wider economic, social, and environmental problems. Behavior change interventions are effective to reduce exposure to harm such as household air pollution, including those using health communications approaches. This article reports the findings of a project that reviewed the effectiveness of behavior change approaches in cleaner cooking interventions in resource-poor settings. The authors synthesized evidence of the use of behavior change techniques, along the cleaner cooking value chain, to bring positive health, economic, and environmental impacts. Forty-eight articles met the inclusion criteria, which documented 55 interventions carried out in 20 countries. The groupings of behavior change techniques most frequently used were shaping knowledge (n = 47), rewards and threats (n = 35), social support (n = 35), and comparisons (n = 16). A scorecard of behavior change effectiveness was developed to analyze a selection of case study interventions. Behavior change techniques have been used effectively as part of multilevel programs. Cooking demonstrations, the right product, and understanding of the barriers and benefits along the value chain have all played a role. Often absent are theories and models of behavior change adapted to the target audience and local context. Robust research methods are needed to track and evaluate behavior change and impact, not just technology disseminated. Behavior change approaches could then play a more prominent role as the “special sauce” in cleaner cooking interventions in resource poor settings.

Optimization of process conditions for Rohu fish in curry medium in retortable pouches using instrumental and sensory characteristics

'Kalia', a popular preparation of Rohu fish, packed in four-layered laminated retort pouch was processed in a steam/air mixture over-pressure retort at 121.1°C to three different F 0 values of 7, 8 and 9min. Time-temperature data were collected during heat processing using an Ellab Sterilization Monitoring System. Texture profile such as hardness, springiness, gumminess and chewiness decreased as the F 0 value increased. The L* values decreased whereas a* and b* values increased with increasing F 0 value. Based on the commercial sterility, sensory evaluation, colour and texture profile analysis, F 0 value of 8min and cook value of 66min, with a total process time of 41.7min at 121.1°C was found satisfactory for the preparation of Rohu fish curry (Kalia) in retort pouches.

저온스팀 열처리 방식에 따른 감자의 전처리 특성

본 연구는 최근 매우 우수한 가열 매체로 인정받고 있는 저온스팀(soft steam) 열처리 공정의 natural convection (NC) 방식과 forced convection-boiler (FC-b) 및 forced convection-fan (FC-f) 방식을 이용하여 처리온도(60, 70, <TEX>$80^{\circ}C$</TEX>) 및 시간(0-60분)에 따른 감자의 전처리 특성을 비교 평가하고자 하였다. 스팀처리 방식에 따른 가열실 내부의 온도변화와 감자 내 외부의 온도변화, 감자의 cook value, ascorbic aicd 및 수분의 함량과 중량감소율의 변화를 관찰한 결과, 모든 처리조건에서 FC-b 및 FC-f의 강제대류 방식에 비해 자연대류의 NC 방식이 이들 전처리 특성에 대해 우수한 결과를 나타냄을 확인할 수 있었다. 따라서, 본 연구의 결과들은 감자의 가공 및 전처리를 위해 현재 사용되고 있는 기존의 열처리 공정에 대한 대안으로써 NC 방식 스팀처리의 높은 효율성 및 산업적 적용에 대한 가능성을 제시하고 있다. This study aimed to investigate the effects of various soft steam treatments, namely, forced convection-boiler, forced convection-fan, and natural convection, on the pretreatment characteristics of potatoes. In this study, potatoes were exposed to various cooking conditions, including steaming method, treatment time (0-60 min), and temperature (60, 70, <TEX>$80^{\circ}C$</TEX>). Then, changes in temperature, cook value, ascorbic acid content, moisture content, and weight loss in the fresh and steam-treated samples were measured and evaluated. The results clearly showed that natural convective steaming was superior to other treatments in terms of heating characteristics, cook value (FC-b: <TEX>$46.4{\pm}1.7$</TEX>, FC-f: <TEX>$21.8{\pm}1.1$</TEX>, NC: <TEX>$52.1{\pm}1.9min$</TEX> at <TEX>$80^{\circ}C$</TEX>), ascorbic acid content (FC-b: <TEX>$36.5{\pm}2.7$</TEX>, FC-f: <TEX>$28.5{\pm}2.9$</TEX>, NC: <TEX>$48.2%{\pm}2.5%$</TEX> at <TEX>$80^{\circ}C$</TEX>), moisture retention (FCb: <TEX>$74.6{\pm}0.8$</TEX>, FC-f: <TEX>$71.5{\pm}0.5$</TEX>, NC: <TEX>$77.6%{\pm}0.4%$</TEX> for 60 min at <TEX>$80^{\circ}C$</TEX>), and weight loss (FC-b: <TEX>$13.9{\pm}0.8$</TEX>, FC-f: <TEX>$15.6{\pm}0.6$</TEX>, NC: <TEX>$10.6%{\pm}0.7%$</TEX> for 60 min at <TEX>$80^{\circ}C$</TEX>) for thermally processed potatoes.

Study of Instrumental and Sensory Characteristics of Catla in Curry Medium during Retort Pouch Processing to Optimize F 0 Value

Catla (Catla catla) fish curry along with potato and peas packed in four-layered laminated retort pouch was processed in a steam/air mixture overpressure retort at 116C to three different F0 values of 5, 7 and 8 min. Time-temperature data were collected during heat processing using an Ellab Sterilization Monitoring System. Texture profiles such as hardness, springiness, gumminess and chewiness decreased as the F0 value increased. The L* values decreased whereas a* and b* values increased with increasing F0 values. Based on the commercial sterility, sensory evaluation, color and texture profile analysis, F0 value of 7 min and cook value of 124 min with a total process time of 55.61 min at 116C was found satisfactory for the development of Catla fish curry in retort pouches. Practical Applications Catla is a commercially important Indian major carp, with white flesh and medium fat content, offer an ideal choice as raw material for the development of ready-to-serve fish products such as fish curry in retort pouches for both domestic and international markets. Sterilization process optimized for ready-to-eat Northeast Indian style Calta fish curry in retort pouch and an F0 value of 7 min was acceptable to the panelists. The process optimized would be useful for commercial application.

Mathematical Modelling of Heat Transfer in Mortadella Bologna PGI during Evaporative Pre-Cooling

Abstract Mortadella evaporative pre-cooling process from 70 to 50°C at core was investigated: the thermal diffusivity and the apparent heat transfer coefficient were experimentally estimated. The effects of ventilation and water spraying with different intervals (0, 5, 10 and 15 min) were tested and core and surface temperatures, cooling times and cook values were compared. Water spraying every 5 min combined with ventilation allowed obtaining both lowest cooling time and cook values in the product. On the contrary, continuous spraying (no interval) presented higher cooling times since probably, after a certain time, water formed a continuous film on product surface, which prevented evaporation. Based on the experimental data, a finite differences mathematical model, previously applied to Mortadella cooking process, was developed and validated by means of two cooling procedures. Acceptable approximation and low percentage errors on final core temperature were obtained, confirming the usefulness and reliability of the proposed model.