Hardeep Singh Gujral

Starch Hydrolyzing Enzymes for Retarding the Staling of Rice Bread

ABSTRACT Previous attempts have been made to obtain gluten-free bread of acceptable quality for bread specific volume and crumb texture. Rice bread is a good alternative to celiac patients, but it has a very rapid staling during storage. Rice starch is more prone to retrograde during storage than wheat starch, and the special hydrophobic nature of the rice proteins requires specific enzymes to be used in the rice bread process. To retard rice bread staling, two different starch hydrolyzing enzymes (α-amylase of intermediate thermostability and cyclodextrin glycoxyl transferase [CGTase]) have been tested and their effect on fresh bread quality and staling during storage has been evaluated. The addition of α-amylase improved bread specific volume and crumb firmness but very sticky textures were obtained. The addition of CGTase produced even higher specific volume and similar crumb firmness with better texture. Both enzymes decreased the ability of amylopectin to retrograde during storage. The firming kineti...

Effect of liquid whole egg, fat and textured soy protein on the textural and cooking properties of raw and baked patties from goat meat

Abstract Effects of addition of liquid whole egg (LWE), fat and textured soy protein (TSP) on textural and cooking properties of goat meat patties were studied. Textural properties of raw and baked patties were measured using an Instron Universal Testing Machine. Regression models were computed for textural and cooking properties as well as overall acceptability scores of patties as a function of LWE, fat and TSP. TSP showed greatest effect on cohesiveness, puncture force, back extrusion force and hardness of both raw and baked patties. While fat showed the highest effect on gumminess, chewiness and adhesiveness of raw patties, LWE improved the juiciness of the patties, lowered the shrinkage and cooking losses. Addition of TSP significantly decreased overall acceptability of baked patties, particularly at highest addition level (20%). The majority of the models had an R2 over 0.9, indicating they are appropriate and can be used to describe the effect of LWE, fat and TSP on textural and cooking properties of goat meat patties.

Some properties of potatoes and their starches. I. Cooking, textural and rheological properties of potatoes

Abstract Three different potato cultivars (Kufri Jyoti, Kufri Badshah and Pukhraj) were analyzed for cooking, sensory, textural and rheological properties. Potato cultivars (Kufri Jyoti and Kufri Badshah) with higher mealiness scores had lower cooking times and compression forces than cultivars with lower mealiness scores (Pukhraj). Kufri Jyoti and Kufri Badshah potatoes also showed higher total solids loss and water uptake values during cooking than Pukhraj potatoes. The cooked potatoes from different cultivars were also evaluated by stress relaxation test and texture profile analysis (TPA). The stress relaxation test for Kufri Jyoti and Kufri Badshah cooked potatoes yielded higher Maxwell elastic moduli (E0, E1 and E3) than Pukhraj cooked potatoes. The viscous moduli (η1,η2 and η3) were found to be significantly lower for Kufri Jyoti cooked potatoes than for Kufri Badshah and Pukhraj. TPA parameters, such as hardness, fracturability, cohesiveness and adhesiveness values, were higher for Kufri Jyoti and Kufri Badshah and were found to be related to elastic factors, such as E0, E1 and E3.

Effect of composite flours and additives on the texture of chapati

Chapaties were prepared from composite flours and the tensile properties of the chapaties were determined using an Instron Universal Testing Machine. Parameters like extensibility, peak force to rupture, modulus of deformation and energy to rupture were used to describe texture. The whole wheat flour was replaced with flours from rice, corn, barley, millets and black gram. Effect of additives like skim milk powder, wet gluten, liquid shortening, carboxymethylcellulose, glycerol monosterate, sodium caseinate and diastase on chapati texture was also evaluated. Upon storage up to 24 h, the extensibility and energy to rupture decreased whereas modulus of deformation and peak load to rupture increased. It was observed that chapaties made from some composite flours showed higher extensibility even after 24 h of storage, especially barley. Some of the additives like wet gluten and sodium caseinate also significantly improved the texture of chapati.

Effect of accelerated aging on the physicochemical and textural properties of brown and milled rice

Accelerated aging of three different rice cultivars varying in length breadth ratio was carried out. Paddy was conditioned to 14%, 18% and 22% moisture content (wet basis) and then steamed for 30 min at atmospheric pressure. The paddy was dehusked to obtain brown rice and then polished to white rice. The physicochemical and textural properties of brown and milled rice were determined using an Instron Universal Testing Machine. Steaming at higher levels of moisture content increased elongation, width expansion, water uptake, cooking time and decreased solids loss. The hardness, cohesiveness and springiness of cooked rice increased whereas its adhesiveness decreased. Accelerated aged rice can be prepared by this short-time process to yield rice that has better and more desirable cooking properties.

Effect of additives on dough development, gaseous release and bread making properties

Abstract The study was carried out to investigate the effect of additives (lactic acid, fat and sodium chloride) and process variables (mixing duration and fermentation temperature) on dough development and gaseous release characteristics measured by Rheofermentometer F2 and bread volume. H m (maximum dough height) was most significantly affected by mixing duration and sodium chloride whereas Hm′ was most significantly affected by fermentation temperature and fat levels. Increased levels of fat (%) showed improving effects on dough development and bread volume, however fat addition did not counteract the adverse affects of over mixing and addition of lactic acid and sodium chloride at higher levels. The models computed had R 2 value ranged between 91.5–98.7%, indicating they are appropriate and can be a useful tool to predict the effect of addition of lactic acid. fat and sodium chloride and process variables mixing duration and fermentation temperature on dough development, gaseous release and bread volume.

Extrusion behaviour of grits from flint and sweet corn

Abstract Studies were conducted to investigate the effect of feed moisture, extrusion temperature and screw speed on the extrusion behaviour and product characteristics of flint and sweet corn grits. The extruder die pressure and extrudate properties, such as expansion and water solubility index (WSI), were analyzed. Second order polynomials were computed to describe the extruder response and product properties of grits from both corn types as a function of feed moisture, extrusion temperature and screw speed. Among feed moisture, extrusion temperature and screw speed, feed moisture showed the most pronounced effect on die pressure, expansion and WSI. Die pressure of the extruder was significantly greater for sweet corn than flint corn grits. The grits from both the corn types differ significantly with respect to extrusion behaviour and product characteristics under similar extrusion conditions. The particle size distribution revealed that flint corn grits had more fine and opaque particles and resulted in extrudates with lower WSI and expansion than those from sweet corn grits which had fewer fine particles.

Effect of skim milk powder, soy protein concentrate and sucrose on the dehydration behaviour, texture, color and acceptability of mango leather

Abstract A study was carried out on the dehydration behaviour, texture, color and sensory acceptability of mango leather. Soy protein concentrate, skim milk powder and sucrose were added at levels of 0%, 4.5% and 9% to improve nutritive value and sweetness of the product. It took 7.60 h of drying time at 60±1°C for mango leather to reach 10% moisture content (wb). The three ingredients lowered the drying rate of mango leather with soy protein concentrate having the most significant effect followed by sucrose and skim milk powder. An objective method for studying the texture of mango leather is presented. The mango leather had an extensibility and energy to rupture of 10.71 mm and 0.1503 J and the extensibility and energy to rupture decreased with increasing levels of soy protein concentrate, skim milk powder and sucrose. Mango leather had L, a and b values of 42.58, 12.58 and 26.89. The yellowness of mango leather as indicated by b values decreased with increase in soy protein concentrate and increased with increase in sucrose. Soy protein concentrate lowered the sensory acceptability of mango leather whereas sucrose and skim milk powder at levels of 4.5% each resulted in mango leather with the highest acceptability. A regression model was developed and coefficients had high R2 values (>0.85) and can be used to predict texture, color, drying time and sensory acceptability.

Effect of Wheat Bran, Coarse Wheat Flour, and Rice Flour on the Instrumental Texture of Cookies

Abstract The effect of replacing wheat flour with wheat bran (0–10%), coarse wheat flour (0–20%) or with rice flour (0–20%) on the quality of cookies was studied. The cookie dough was subjected to Instrumental Texture Profile Analysis in order to determine dough cohesiveness and adhesiveness. After baking spread factor, puncture force and fracture strength of the cookies was also determined. The control dough had cohesiveness and adhesiveness values of 0.279 and 13.6 N s whereas control cookies had puncture force and fracture strength of 90.84 N and 100.16 N. Wheat bran increased dough cohesiveness and adhesiveness whereas coarse wheat flour had the opposite effect. Increasing levels of rice flour decreased cohesiveness but increased adhesiveness. Wheat bran and rice flour lowered the spread factor where as coarse wheat flour increased spread factor. Coarse wheat flour and rice flour lowered the fracture strength where as wheat bran increased fracture strength. Sensory evaluation revealed that increasing levels of wheat bran lowered the overall acceptability whereas rice flour and coarse wheat flour improved sensory scores.

Phenolic Content and Antioxidant Activity of Germinated and Cooked Pulses

Five commonly consumed pulses, Mah (Vigna mungo), Green mung (Vigna radiata), Arhar (Cajanas cajan), Masur (Lens esculantus), and Moth (Vigna aconitifolia), were studied for their total phenolic content and antioxidant activity after germination (12 and 24 h) and pressure cooking. Arhar had the highest total phenolic content (6.71 mg ferulic acid/g flour) whereas Moth had the least (1.54 mg/g). All pulses, except Moth, showed a significant decrease in total phenolic content after germination. The antioxidant activity of the pulses varied from 10.61 to 36.38% (DPPH radical scavenging activity), which significantly decreased with germination in all pulses except Moth. The total phenolic content highly correlated with the antioxidant activity in the pulses. Cooking lowered the total phenolic content by 10–45% and antioxidant activity by 27–68% in the control and germinated pulses.