PARTIAL SUBSTITUTION OF SODIUM CHLORIDE BY POTASSIUM CHLORIDE IN FRANKFURTER FORMULATIONS

Substitution of a portion of the sodium chloride by potassium chloride in frankfurter formulations in order to decrease dietary sodium intake had little effect on the physical characteristics of the frankfurter or its sensory evaluation. Replacements of up to 50% of added sodium chloride with potassium chloride provided an acceptable flavor without excessive bitterness, and reduced total sodium content by 37%. The commercial spice mixture contributed substantially to the sodium levels in the frankfurters.     

BOUND WATER IN FRUIT PRODUCTS BY THE FREEZING METHOD

SUMMARY— An insulated heat-sink containing Freon-12® (N.B.P. −21.6°F) provides a reproducible system for measurement of thermal properties of fruit products. The difference in time required to remove the latent heat of fusion of the "eutectic" mixture in comparison with distilled water measures the "bound" water. The 34-37%"bound" water in papaya (var. solo) pulp is unaffected by varying pH in the range 3.0–6.0. Less than 10% water is bound in guava, passion fruit and pineapple juice products with up to 35% sucrose added. Thermal conductivity of the solid phase "eutectic" mixture in the 5–50% soluble solids range fits the regression Y = AB^x, Y = (3.69) (0.96)^x where x = percent total soluble solids (TSS) and Y = thermal conductivity (Cal x 10³/(cm²) (sec) (°C/cm)). The relationship of freezing point to TSS values as 1.10 + 0.64 (TSS) in the test system is significant (P < 0.01) in the range 5–50% TSS. The time for fusion (θ_w) of sucrose/water in the range 5–50% TSS fits the regression: log θ_w= (−0.8325) (−0.0165) (TSS) or θ_w= (0.984) (0.164)^TSS sec. Addition of solutes such as sucrose will inhibit gelation without affecting "bound" water values. Pectin gel structures apparently are dependent on secondary bonding and independent of "bound" water per se.     

用"曲拉"生产工业干酪素的工艺改进研究

通过对用“曲拉”生产工业干酪素生产工艺的研究,对溶解、酸化、清洗等工艺进行了改进,然后在改进后的工艺的基础上选择护色剂,最后确定了溶解温度50～60℃,溶解时间50～30min,溶解pH 8.5～9.0,点酸凝制pH4.2～4.0,氢氧化钠添加0.04%护色剂做溶剂,稀盐酸做凝固剂,干燥温度50～60℃,真空度-540～580 mmHg,干燥时间为2～3h等工艺条件.简化了曲拉精加工工艺,使产品的质量提高,产率可达78.25%.     

THERMAL STABILIZATION OF FOUR MICROBIAL β-GALACTOSIDASES BY HISTIDINE, CASEIN AMINO ACIDS AND CASEIN

Thermal stability of four microbial β-galactosidases was evaluated in the presence of casein, casein amino acids and histidine. The enzymes from Esch-erichia coli, Kluyveromyces marxianus and Streptococcus thermophilus were stabilized up to 60 fold by these additives, but there was little effect on the enzyme from Aspergillus oryzae. Stabilization by casein amino acids and histidine was largely lactose dependent. Casein amino acids were not as effective as casein for any enzyme. For the K. marxianus enzyme, histidine alone was as effective as casein and the stabilizing effect was proportional to the logarithm of the histidine concentration.     

INSTABILITY OF SODIUM NITRITE IN A CHEMICALLY DEFINED MICROBIOLOGICAL MEDIUM

Mixtures of sodium nitrite, amino acids and ascorbic acid at pH 6.3 or 7.2 were filter sterilized or heated for various times at 121°C. Samples were analyzed for nitrite concentration immediately after treatment and after storage at 37 or 43°C. Heating the complete medium for 15 min at 121°C reduced the nitrite concentration by 30–50% independent of the initial nitrite concentration. Storage of complete filter sterilized medium at 43°C for 18–24 hr resulted in 50–65% loss of nitrite while in heat sterilized medium the loss was as great as 90%. None of the 19 amino acids stored individually with sodium nitrite at 37°C for up to 4 hr affected the nitrite concentration, whereas ascorbic acid resulted in total disappearance of nitrite. During heating at 121°C of the 19 amino acids only cystine resulted in any significant nitrite loss after 15 min of treatment while ascorbic acid effected total nitrite disappearance after 5 min. The defined medium containing nitrite demonstrated inhibitory activity against seven strains of Clostridium perfringens.     

EFFECT OF SODIUM CHLORIDE CONCENTRATION ON CALCIUM UPTAKE INTO BRINED CUCUMBERS1

Calcium from a CaCl₂ brine approximately iso-osmotic with cucumber cell sap penetrated cucumber fruit much more slowly than did calcium ions from a NaCl + CaCl₂ brine supra-osmotic with cucumber cell sap. After 96 h calcium that penetrated from the iso-osmotic brine was localized mostly in the exocarp and relatively little in the interior tissues, while calcium that penetrated from the supra-osmotic brine reached higher concentrations and was more evenly distributed among the exocarp, mesocarp, and endocarp sections.