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Chicken breast meat is traditionally marinated to improve tenderness and juiciness. However, a significant amount of marinade is purged during cooking. It was envisioned that preheating of marinated chicken breast meat would minimize the purge due to presetting the myofibrillar proteins and will give higher cook yield. The preheating was done in a radiofrequency (RF) oven to provide uniform heating within the volume of the product, and to allow extra marinade retention. Two preheating regimens, 20–30°C and 55–60°C were selected. A 3–4% marinade gain was obtained while the meat was preheated in RF with 10% extra marinade but this gain was not significantly different in the four treatments and the control (p > .05). The cooked meat yields were determined as a function of programmed preheating of marinated meat in the RF oven, followed by final cooking of the product in the air impingement oven. The programmed preheated samples at 20–30°C showed higher cook yield (96.11–100.51%) as compared to the control (95.6%). However, all the samples heated at 55–60°C showed higher cook yield (100.57–109.39%). Warner-Bratzler shear tests were performed on cooked samples to determine the quality of RF preheated product, and the quality of the RF-treated product was not much different from that of the product cooked directly in a conventional air oven.

Instrumental and sensory quality of potato strips baked in a radiant wall oven was evaluated and compared to deep-fat fried and conventional oven baked samples. Even though radiant wall oven baked potato strips had one-fourth the fat content of the deep-fat fried samples, there was no significant difference in chroma, cutting and puncture force of radiant wall oven baked and deep-fat fried samples. Consumer acceptability of radiant wall oven baked potato strips was 65.7 and 85.7% before and after revealing the nutrition facts, respectively. Both were lower than acceptability of deep-fat fried samples. However, 36.5% of consumers were willing to purchase radiant wall oven baked samples.

Soymilk was prepared from boiled and unboiled comminuted suspensions of dehulled soybean and water using pressurized homogenization (one pass and two pass). Particle size showed significant differences between soymilks homogenized by one pass and two pass. Apparent viscosities and total solid contents showed significant differences between boiled and unboiled treatments. Soymilks exhibited pseudoplastic and thixotropic behavior and Arrhenius model was fitted to express temperature dependence of apparent viscosity. Microscopic images showed hydrated, separated, uniformly distributed, and homogeneous particles in boiled two-pass soymilk as they were disrupted easily and it was selected as the best treatment for processing soymilk containing all of the soybean solids.

Various emulsifying salt mixtures were used in making block type processed cheeses. Ras cheese was used as the cheese base with two salt mixtures: (i) Na-diphosphate + Na-polyphosphate + Na-tripolyphosphate and (ii) Na-poly-phosphate + Na-citrate + Na-orthophosphate + Na-diphosphate comparing to commercial salts Joha SE and PZO respectively. The resultant processed cheeses were analyzed when fresh and monthly during storage at 7 and 20°C for water activity (a w ), oil separation, meltability, flow behavior, color parameters, and sensory properties. There were no significant differences in water activity values among all treatments. The differences were significant in oil index and meltability values. The samples exhibited different shear stress values and it was highest in treatments with commercial salts. Consistency coefficient (k-value) of processed cheese samples was affected by emulsifying salt mixture being almost two folds higher with salt mixtures (i) than those of salt mixtures (ii). The...

The rheological behavior of banana puree was determined using a dynamic stress rheometer with a pressure couette fixture, which allowed experiments to be conducted at high temperature. The pressure couette was pressurized with compressed air to 206.8 kPa (gage pressure) and experiments were carried out at temperatures ranging from 30 to 120°C. The shear stress values ranged from 10 to 170 Pa and the shear rate values from 10−5 to 103 s−1. The model that best fitted the experimental data at all temperatures was the Herschel-Bulkley model. There was a usual tendency for the apparent viscosity to decrease with increasing temperature but an increase in apparent viscosity with increasing from 50 to 60°C and from 110 to 120°C was found. This could be due to interaction of polysaccharides present in banana puree. There was a slight difference between the apparent viscosity values for increasing shear stress sweeps and those for the decreasing shear stress sweeps suggesting time dependency of the rheolog...

Processed cheese spreads were produced using Ras cheese as the cheese base with salt mixtures (i) Na‐pyrophosphate + Na‐polyphosphate, (ii) Na‐pyrophosphate + Na‐polyphosphate + Na‐tripolyphosphate, and (iii) Na‐pyrophosphate + Na‐polyphosphate + Na‐orthphosphate + Na‐tripolyphosphate. For comparison, cheese spreads were also made with commercial emulsifying salts JOHA S10, S9 special, and NO. Texture profile analysis showed that the values of chewiness, gumminess, adhesiveness, and hardness were significantly different for various treatments. Also, the texture profile values increased upon storage and were highest in the samples stored at room temperature. The light microscopy photographs indicated different emulsification degree with various emulsifying salt mixtures. These observations were also confirmed with the image analysis and Transmission Electron Microscopy.

Processed cheese spreads were produced using Ras cheese and various emulsifying salt mixtures. Acidified Ras cheese (2 months old) was used as the cheese base and blended with following emulsifying salt mixtures: (i) Na‐pyrophosphate + Na‐polyphosphate, (ii) Na‐pyrophosphate + Na‐polyphosphate + Na‐tripolyphosphate, and (iii) Na‐pyrophosphate + Na‐polyphosphate + Na‐orthophosphate + Na‐tripolyphosphate. The control cheese spreads were also made with commercial emulsifying salts, Joha S10, S9s, and NO. Water activity, oil index, meltability, flow behavior, color parameters and sensory evaluations for the resultant processed cheese were studied. Cheeses showed slight differences in water activity while the differences were significant in oil index and meltability values. Shear stress of the processed cheese samples measured at 60°C was different from that of the control. It was dependent upon the individual salts in emulsifying mixture. Spreadable Ras cheese was shinier in treatment (iii) and exhib...

The objective of this study was to determine two important rheological properties, fracturability and toughness, of deep fried tortilla chips which are prepared with the addition of hydrocolloids using texture analyzer with Kramer‐shear cell. Low, medium and high viscosity carboxymethyl cellulose, and Xanthan gum were used as hydro‐colloids. For each material, different concentrations were added into the formula for tortilla during dough formation to determine the effect of different concentrations on the rheological properties. Tortilla chips were deep fried in pure vegetable oil for several frying times to investigate the effect of frying time. It was found that with increasing concentration of hydrocolloids, force required to break the tortilla chips increased, thus toughness, and fracturability values increased. However, longer frying times resulted in more fragile tortilla chips with reduced fracturability.

Rheological behavior of soybean milk at various solid contents (9%‐16% w/w) was measured using an oscillatory viscometer under turbulent flow conditions (Reynolds number between 3116 and 12000) in a temperature range of 60‐140°C. The power law model expressed as τ=KγN was found to be the most appropriate for the rheological model of soybean milk. The apparent viscosity using an oscillatory viscometer was not affected by the flow rate. The equations describing the effects of temperature and concentration on rheological parameters (n, K) were developed within the aseptic processing temperature range. The parameter “K”; significantly decreased with increasing temperature, while the parameter “n”; slightly increased with temperature. However, the concentration effect on parameter “K”; and “n”; were opposite to that of the temperature effect.