Effects of Pretreatment and Dehydration Temperature on Color, Nutrient Retention and Sensory Characteristics of Okra

Moisture content, water activity, color, and concentrations of ascorbic acid and thiamin of blanched (boiling water with or without 0.1% SO₂) and unblanched okra, dried for 10 hr at 63°C or 14 hr at 52°C, were determined before and after 6 wk storage at ambient temperature. Sensory characteristics were evaluated after storage and rehydration of okra slices. Blanching in boiling water with or without 0.1% SO₂ resulted in protection of the characteristic flavor of okra. Blanching in SO₂ solution before dehydration produced greater ascorbic acid retention (p < 0.05) but a substantial loss of thiamine (p ≤ 0.05).     

Lactobacillus plantarum and Enterobacter Cloacae Growth In Cucumber Extracts Containing Various Salts

Salt substitutes included chlorides, sulfates and phosphates at 25%, 50% and 100% ionic strength equivalent to a concentration of 1M NaCl. At 100% NaCl substitution, chloride salts provided the most selective environment and sulfates showed no selectivity, whereas phosphates suppressed microbial, growth. Substitution of sulfates for NaCl generally increased generation times for both microorganisms. Substitution of KCl for NaCl at 50%, resulted in more selective growth of L. plantarum than in those with either KCl or NaCl alone. KCl was the only chloride substitute allowing growth of E. cloacae. Substitution of phosphates for NaCl at 50% enabled slow growth of L. plantarum.     

TEXTURAL GAIN AND SUBSEQUENT LOSS IN IRRADIATED APPLES, CARROTS AND POTATOES WITH INCREASE IN DOSE FROM 0.03 TO 1.0 kGy

Cored samples (16mm × 15mm diameter) of apples, carrots and potatoes were irradiated in an Isomedix Gammacell 1000 irradiator at a dose rate of approximately 9Gy/min. Texture was measured using unrestrained uniaxial compression to microrupture on the JJ Universal Testing Machine. The loading rate was 6mm/min. Texture or firmness was assessed as the force to microrupture; the force required for various microrupture sample deformations (25%, 50% and 75%); the apparent Young's Modulus (ratio of the average stress to the average strain to microrupture); and the microrupture energy (area under the force-deformation curve). As the dose increased from 0.03 up to about 0.1 kGy, a gain in texture generally occurred in all products ranging from 3% to 16%. A transition area from gain to loss occurred within the 0.1 to 0.3 kGy range. Loss of texture occurred in all products as the dose increased from 0.3 to 1.0kGy, the loss ranging from 4% to 30%. The greatest loss of texture occurred in apples and the least loss in carrots. There textural trends may have commercial significance in low dose irradiation processes such as sprout inhibition, senescence delay and disinfestation.     

Roasting vs Cooking in a Model System: Tenderness of Bull Adductor Muscle, Conventionally Chilled or Electrically Stimulated—Hot Boned

Conventionally chilled (CC) and electrically stimulated-hot boned (ESHB) bull adductor muscles roasted to 70° C, or muscle strips cooked in a model system (waterbath) to 70° C were compared. Sensory tenderness and texture (mealiness) and Instron texture characteristics were not affected significantly by the cooking system. Differences between carcass treatments (CC, ESHB) for sensory tenderness and texture were significant, but small. Percentage solubilized hydroxyproline did not have a major influence on sensory tenderness or texture, or on Instron texture characteristics of the muscle. Sensory tenderness and texture were related more to Instron cohesiveness and firmness than they were to Instron penetration measurements.     

Growth of Lactobacillus plantarum in Cucumber Extract Containing Various Chloride Salts

Systems similar to the environment of pure-culture inoculation and the natural process of cucumber fermentation were used to study the capabilities of some salt substitutes including potassium chloride, calcium chloride, and magnesium chloride to provide a selective environment for the growth of Lactobacillus plantarum, a desirable species in cucumber fermentation. The salt that gave the highest percentage of Lactobacillus in the total microbial population was considered to provide the most selective environment for the desirable organisms in cucumber fermentation. Salts that provided the most selective environment were NaCl and KCl in the filtered, raw cucumber extract and KCl in the heated and filtered extract. Calcium chloride was more selective than MgCl₂ in either medium.