David R. Woodward

Calcium diglutamate improves taste characteristics of lower-salt soup.

Objective: To ascertain (1) whether the taste characteristics of a conventionally-salted (150 mM NaCl) soup can be reproduced in soups of substantially lower NaCl level with the help of added glutamate, and (2) whether calcium diglutamate (CDG) is equivalent to monosodium glutamate (MSG) in its effect on the taste of soup.Design: Cross-sectional, with multiple measurements on each subject.Setting: Healthy university students.Subjects: A total of 107 volunteers, recruited by on-campus advertising.Methods: Subjects tasted 32 soups, with all possible combinations of four NaCl concentrations (0–150 mM), four glutamate levels (0–43 mM), and two glutamate types (MSG, CDG).Main outcome measures: Ratings of each soup on six scales (liking, flavour-intensity, familiarity, naturalness of taste, richness of taste, saltiness).Results: A 50 or 85 mM NaCl soup with added CDG or MSG is rated as high as, or higher than, a 150 mM NaCl soup free of added glutamate on five of the six scales (the exception being saltiness). CDG and MSG have equivalent effects.Conclusions: Addition of glutamate allows substantial reductions in Na content of soup, without significant deterioration of taste. CDG and MSG have equivalent effects, but use of CDG permits a greater reduction in Na intake.Sponsorship: We acknowledge the financial support of the International Glutamate Technical Committee (IGTC).

Human milk fat content: Within-feed variation

Changes in milk fat content during individual breast-feeds were studied using a modification of the interrupted feed technique (Woolridge et al. (1982): Early Human Dev., 6, 265-272). Each feed was interrupted once, for weighing the baby and obtaining a small milk sample; weighing and milk sampling were also done at the start and end of the feed from that breast. Mathematical analysis of 52 feeds from the first breast offered at a feeding episode, and 39 second-breast feeds, showed a similar pattern on both types. The fat content rose in line with (Vi/Ve)1.35 (V being the volume consumed since the feed from that breast began). However, first-breast feeds showed sharp initial and final rises in fat content. The authors propose a mechanism to explain the difference in pattern between first- and second-breast feeds.

Urban‐rural differences in dietary habits and influences among Australian adolescents

Junior high school students (2,082) in Tasmania, Australia, were surveyed using a printed questionnaire. For 22 commonly‐used foods collectively, MANOVA indicated that rural students differed significantly from urban students in their consumption frequency for the foods, their perception of the usage of the foods by their parents and their friends, their liking for the foods and their perceptions of those foods’ healthfulness. Regression analyses for the 22 foods separately indicated that liking for a food and parental usage of it were generally significantly linked to the respondents frequency of using it; there were few urban‐rural differences in this pattern. A foods healthfulness (as perceived by the respondent) and friends’ usage of it were significantly linked to personal usage frequency only for a minority of foods; the regression analyses suggested that rural students gave less weight than urban students to health considerations and to perceived peer behavior in their food choices. These results suggest differences in food cognition between urban and rural adolescents.

Dietary studies on Tasmanian high school students: intakes of energy and nutrients.

ABSTRACT. In July 1979 the authors obtained 24‐hour diet records from 1055 students in school‐grades 7–10 (age‐range 11–16 years) in Tasmania, Australia. For ages 12–15, our respondents appear representative of the Tasmanian population.

Do ambient temperature and humidity influence the breast-milk intake of babies ?

Abstract This study explored the possible effect of ambient temperature and humidity on the breast‐milk intakes of Australian infants (n= 35) aged 6–12 weeks. Over a 24 h period, each baby was fed only on milk from the breast; milk intakes, temperature and humidity were monitored. Milk intakes—determined by test‐weighing the baby, with a correction for evaporative losses during feeds—showed a mean of 830 g/24 h, with median 818 and s.d. 152. The mean correction for evaporative losses was 46 g/24 h; omission of this correction would have led to an average underestimate of 5.5% in 24 h intakes. Ambient conditions varied substantially between subjects: 24 h mean temperatures ranged from 14 to 28°C, and humidities from 48 to 97%. Over these ranges, breast‐milk intakes did not appear to be significantly influenced by ambient temperature or ambient humidity; however, the rate of evaporative losses increased by 0.008 g/min for each 1°C rise in ambient temperature.

Is the “Difference index” useful for assessment of protein relatedness?

Abstract This paper assesses the usefulness of the Difference Index (Metzger, Shapiro, Mosimann & Vinton, 1968) for predicting, from amino acid compositions, whether two proteins are related or unrelated. It is concluded that, with a 5 % probability of false identification, Difference Index values less than 10-0 indicate relatedness and values greater than 26·8 indicate unrelatedness. A large proportion of protein pairs have Difference Index values in the region 10·0–26·8 and cannot therefore be reliably identified as related or unrelated by this criterion.