Allergens are proteins and are, therefore, likely to be denatured when subjected to thermal treatment. Traditional cooking has so far been able to reduce allergen sensitivity by around 70–90%. This study was aimed at evaluating the effect of a broad range of thermal treatments on the reduction of soy immunoreactivity (IR) in a 5% slurry using a sandwich ELISA technique. Cooking at 100 °C (10–60 min) and different thermal processing conditions, such as in commercial sterilization (with a process lethality (Fo) between 3 and 5 min) and selected severe thermal processing conditions (Fo > 5 and up to 23 min) were used in the study to evaluate their influence on allergen IR. Based on an IR comparison with an internal soy allergen standard, the allergen concentration in the untreated soy sample was calculated to be equivalent to 333 mg/kg (ppm). Cooking conditions only reduced the IR sensitivity to about 10 mg/kg (~1.5 log reductions), while the thermal processing treatments lowered the allergen IR up to 23 × 10−3 mg/kg (or 23 ppb) (>4 log reductions). FTIR analysis indicated significant changes in protein structure resulting from the thermal processing treatments, with a higher degree of allergen reduction corresponding with a higher value of random coil percentages. The influence of process severity on color and rheological properties was, however, minimal.
Soy proteins are globular in nature and are resistant to denaturation with lower intensity thermal treatments like cooking. Likewise, germination can also alter the protein structure through the activity of various enzymes and sonication can disrupt the molecular structure through cavitation and other ultrasound effects, and contribute to some reduction in immunoreactivity (IR) of allergens. This study evaluated the effects of germination and sonication pretreatment in combination with common cooking on lowering the soy allergen IR. Germination was carried out for up to 120 h and ultrasound sonication treatments were given for 20, 40 and 60 min at room temperature. Cooking at 100 oC was carried out for 10 to 60 min. The soy allergen IR was evaluated using a commercial sandwich ELISA kit. The combined action of germination, sonication and cooking helped to reduce the soy allergen IR to single digit mg/L levels from the nearly 400 mg/L initial level in the 5% soy slurry (> 99% reduction). These levels are lower than the reported threshold values of soy allergens in foods. In addition, the germination and ultrasound process was shown to reduce the anti-nutritional properties and enhance the phenolic and radical scavenging activity by over 50%.
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).
Post-harvest loss is very common in seasonal fruits due to its high perishability even under refrigerated conditions. Value addition and processing is the best solution to overcome this problem and it also ensures the availability of the product round the year. This study is to develop jackfruit leather that replicates the natural fruit taste and is shelf stable at room temperature (28 ± 2°C). The product contributes 3.63Kcal/g to the energy requirement and is rich in minerals like potassium and sodium (7442μg/g and 1842μg/g, respectively). Sorption isotherm studies showed a sigmoid characteristic for the product. It has a critical moisture content of 48.39±0.44% with respect to 96% relative humidity and a water activity of 0.47. The product was packed in different packaging materials like 220-gauge polyethylene laminated with 50-gauge metalized polyester (Met PE) and 150 gauge Biaxially Oriented Poly Propylene (BOPP) laminated with 50-gauge polyester to study and compare its shelf-life in both the packaging materials at room temperature (28 ± 2°C). Physical and chemical parameters of the product was analyzed during the period of storage and the results revealed a shelf stability for 90 days for the product packed in both the packaging materials.
Chocolate is a very popular food product that is relished by millions of people for its unique, rich and sweet taste. The health benefits of chocolate are immense which is attributed to its high polyphenolic content. In the current study, the diet chocolates using natural and artificial sweeteners were developed. Also, the jackfruit seed powder after fermentation (anaerobic and aerobic) was used to replace cocoa powder by 10%. The physiochemical and glycemic index of the chocolates were analyzed. The physiochemical analysis of the chocolates indicated that substitution of jackfruit seed powder did not alter significantly the proximate composition. It was found out that the glycemic index and glycemic load of the chocolates were significantly lower than commercial milk chocolate, which makes it a suitable food product for diabetic and other groups. The samples were packed in pouches made of metallised polyester films laminated with polyethylene for storage studies. Instrumental textural studies were in concordance with sensory observation, indicating that the product remained stable for 3 months at room temperature (26°C ± 2°C). The color of the product remained similar throughout the storage period indicating stable structural and surface characteristics. Hence, the chocolates developed using natural and artificial sweeteners have low GI and will minimize the risk of several chronic diseases including diabetes and the use of jackfruit seed powder as a substitute for cocoa powder has not altered any of the characteristic features of chocolate.
Fiber intake improves gut health and prevents non-communicable diseases. The current study investigates the substitution of carrageenan in white bread and evaluates its effect on the physiochemical and structural characteristics of bread. The 100% wheat flour was used as control and the test sample contained 4% carrageenan. The physio-chemical analysis showed that carrageenan-substitution improved the hydration properties of the flour (WHC—1.33 g/g; SC—3.50 ml/g). Carrageen substituted bread had reduced the loaf volume. The fiber content in carrageenan-substituted bread was noticeably higher (9.4 g%) than control (3.5 g%). Crude lipid (4.6 g%) and protein (7.0 g%) content improved with carrageenan-substitution. The mineral contents (Na, K, Mg, Ca, Fe, and Zn) were increased in carrageenan-breads. The texture profile analysis showed a decreased hardness (H1—92.3 N, H2—62.5 N) and improved springiness (5.3 mm) in carrageenan-bread.