Hydrophobicity of bitter peptides from soy protein hydrolysates.

Soy peptides were characterized for flavor, chemical properties, and hydrophobicity to investigate their relationships with bitterness. Five peptide fractions ranging in average molecular mass from 580 to 11300 Da were fractionated by ultrafiltration from two commercial soy protein hydrolysates. The bitterness of fractionated peptides was related to molecular mass, with maximum bitterness observed at approximately 4000 Da for one hydrolysate and 2000 Da for the other. The bitterness increased as the peptide M(w) decreased to 3000 Da for the first hydrolysate and to 2000 Da for the second one and then decreased as the peptide M(w) decreased below 1000 Da. The peptide fraction with molecular mass of <1000 Da showed the lowest bitterness for both. The hydrophobicity data based on Q values do not support Ney's Q rule as a predictor of bitterness for soy peptides.

Thermal Destruction of Listeria monocytogenes in Ground Pork Prepared with and without Soy Hulls.

D-values and z-values were determined for Listeria monocytogenes Scott A cells heated in raw ground pork prepared with and without soy hulls and in a soy hull/water mixture. Products inoculated with ca. 107 colony-forming units (CFU) per g were sealed in glass vials, immersed in a water bath, and held at 50, 55, 60, or 62°C for predetermined times. Survival was determined by testing heated samples with McBride listeria agar. The D-values for L. monocytogenes cells at 50, 55, and 60°C were 108.81, 9.80, and 1.14 min, respectively, when heating was in ground pork and 113.64, 10.19, and 1.70 min, respectively, when heating in ground pork with added soy hulls. At 62°C L. monocytogenes cells were inactivated too rapidly to permit determination of the D-value. The D-values for L. monocytogenes in the soy hull/water mixture at 50 and 55°C were 19.84 and 3.94 min, respectively. L. monocytogenes cells were inactivated too quickly to determine the D-value at 60°C. The z-values for L. monocytogenes in ground pork prepared with and without soy hulls were 5.45 and 5.05°C, respectively. If ground pork naturally contains 102 L. monocytogenes cells per g and if we want to assure safety with a 4-D Listeria cook (reducing the L. monocytogenes population by four orders of magniatude), then according to results of this study, ground pork must be heated to an internal temperature of 60°C for at least 4.6 min and ground pork with added soy hulls for at least 6.8 min.

Overview of Foodservice Energy Research: Heat Processing 1, 2.

A conceptual framework for factors affecting energy usage for heat processing in United States foodservice operations was developed and used to analyze the direction of foodservice energy research in this area. The literature was reviewed from 1930 to 1981. Most research has been related to alternate food product flows within foodservice operations and to increasing the operating efficiency of foodservice equipment. Some researchers have studied the effect of altering operating parameters upon energy expended per unit of production. Due to research cost constraints, ground beef has been a frequently studied commodity. Research using economical bentonite-water dispersions for food models during foodservice energy research was included. Activities involving the energy-modification of recipes, revealed energy savings from 11-79%. The need for research methodologies for foodservice energy research was delineated to study all variables, including microbial quality and safety, which influence energy usage during heat processing.

Excessive Energy for Food Distribution Associated with Food Seizures 1, 2.

Energy expended to distribute food shipments during a 2-year period to, and within, the United States before their seizure was documented for four distribution modes: ship, truck, train and air. The food shipments were described according to their wholesale value, energy usage per distribution mode, nutrient content, energy/nutrient ratios and violation code(s) of the Food, Drug and Cosmetic Act. Results were used to illustrate how this type of study could be used as an administrative tool to develop strategies for avoiding excessive energy consumption during food distribution. Recommendations were made for collecting further data to facilitate reductions in the amount of energy used to distribute human food. Finally, rather ethical questions were raised about the problem of purchasing protein foods from less-developed countries; using energy to distribute them to the United States when they are subsequently declared unfit for human consumption.

A Justifiable Food-Energy-Legislative Triangle? 1, 2.

A conceptual model of the food-energy-legislative triangle within the United States food industry is presented. The scope of the triangle is pictorially represented. Each apex of the triangle is defined and examples are given to illustrate the interrelationships among them. The triangle includes all nutritious and nonnutritious foods produced; all direct and indirect energy used to produce, process, distribute and consume foods and all food-related legislation. Recent examples were chosen to illustrate how changes in one apex of the triangle affect components of the other two apexes. An analogy was drawn between the Bermuda and food-energy-legislative triangles to illustrate that the level of apathy towards solving the Bermuda Triangle cannot be tolerated for the latter triangle. Recommendations are given for using sound resource management techniques to identify all interdependencies in the food-energy-legislative triangle and thus increase the effectiveness of national policies affecting the food industry.

Hospital Foodservice - 1978 and Beyond.

This paper (a) discusses how changes within the health care and food processing industries have influenced development of alternate foodservice systems and (b) projects some future trends related to resource usage. Schematic diagrams for four alternate foodservice systems are presented and discussed. The need for strengthening cooperation among food processing and foodservice industries is emphasized. Research activities related to the quality and safety of foods within each of these systems have been limited. In addition, these foodservice systems evolved without adequate consideration of effective use of energy resources. In the future, food processors and foodservice managers will have to coordinate their functions to serve good quality, energy-efficient menu items.