Relationship Between Blocked Lysine and Carbohydrate Composition of Infant Formulas

The quantity of blocked lysine in spray-dried infant formulas in Italy was calculated by the furosine method. This quantity was then correlated with the composition of the carbohydrate fraction. In formulas containing only lactose as carbohydrate its presence in large quantities (6.7–7.5 g/100 mL of formula as fed), with a lysine-rich protein fraction, may lead to amino acid blocking of >20%. In formulas in which lactose was substituted with low-DE maltodextrin a reduction of lysine blocking was possible. Addition of glucose may result in high levels of blocked lysine.     

Kinetics of Deteriorative Reactions in Model Food Systems of High Water Activity: Color Changes Due to Nonenzymatic Browning

Conventional food preservation methods by adjustment of water activity (a^w) have adverse effects on the flavor of the finished product. Recent research showed that a mild reduction of a, (i.e. to 0.90 - 0.95) together with other factors will produce microbiologically stable products. The purpose of this work was to determine the kinetics of brown color development in model systems adjusted to the range of a^w 0.90 - 0.95. From results obtained one can see the strong influence of temperature and pH and the lack of influence of a^w in the rate of brown color development.     

Direct measurement of hydraulic properties in developing berries of Vitis vinifera L. cv Shiraz and Chardonnay

Berries of Vitis vinifera L. cv Shiraz can undergo weight loss during later stages of ripening. Existing published views on how weight loss occurs are based on changes in capacity of the vascular system to import water during development (McCarthy and Coombe, Australian Journal of Grape and Wine Research, 5, 17–21, 1999). One important element of these views is the proposed cessation of water flow through the xylem after veraison. We have now measured the water flow into berries of Shiraz and Chardonnay as they develop using the pressure probe and the high pressure flow meter (HPFM). The pressure probe connected to the pedicel of individual berries provided measurements of single berry hydraulic conductance. By systematic excision of tissue segments of the berry and pedicel we determined where in the pathway hydraulic conductance changed during development. The HPFM was used on whole bunches showing that berries (including pedicels) represent parallel high hydraulic resistances and that the hydraulic resistance of the bunch axis was rather small. The hydraulic conductance per berry could be determined from excision experiments. There was close agreement between the pressure probe and HPFM measurements. Both showed a ten‐fold reduction in hydraulic conductance of whole berries from veraison to full ripeness. Shiraz had hydraulic conductances that were 2‐ to 5‐fold higher than those for Chardonnay. Shiraz maintained a higher hydraulic conductance past 90 days after flowering than Chardonnay. The decrease in hydraulic conductance occurred in both the distal and proximal parts of the berry for both varieties. The pressure probe also provided measurements of the xylem pressure that non‐transpiring berries could develop. These pressures were –0.2 to –0.1 MPa until veraison and increased to zero when the juice osmotic potential reached about –3 MPa in Chardonnay and –4 MPa in Shiraz. The results suggest values of the reflection coefficient of the osmotic barrier around the xylem vessels of about 0.1–0.2 at veraison decreasing to 0 at harvest. It is suggested that in addition to changes in xylem anatomy, aquaporins in berry membranes may play a role in regulating hydraulic conductance. Water movement from the berry back to the parent vine via the xylem (backflow) may be an important component of berry weight loss in Shiraz, particularly if the phloem ceases functioning at high osmotic potentials near maximum weight. Backflow could account for a weight loss of 43 mg per day in Shiraz berries for a relatively small gradient of 0.1 MPa.     

RHEOLOGY OF WHEAT DOUGHS FOR FRESH PASTA PRODUCTION: INFLUENCE OF SEMOLINA-FLOUR BLENDS AND SALT CONTENT

Dynamic measurements were made with a controlled stress rheometer to study the viscoelastic properties (G', G', δ) of wheat doughs (45% wb water content) for fresh pasta production prepared with different blends of durum wheat semolina and common wheat flour with different concentrations of sodium chloride. Increasing the semolina and sodium chloride content, increased the strength and the solid-like behaviour of semolina-flour blends. The physical properties of dough were strongly dependent on particle size distribution and salt addition. By manipulating semolina-flour ratio and ionic strength, it was possible to obtain semolina-flour doughs with a rheological behaviour close to that of pure semolina dough.     

FOR NONLINEARITY IN THE HEARTBEAT TIME SERIES

Hearbeat time series obtained by Holter monitoring of 10 healthy subjects are studied using a nonlinear predictor S map . The normalized prediction error was calculated as a function of the model control parameter in order to get information on the amount of nonlinearity in the data. Moreover, to search for possible chaotic behavior, the linear correlation coefficient between predicted and real values was calculated as a function of the prediction time. The results of this analysis reveal no clear evidence of chaoticness or nonlinearity in the data. Moreover, for 8 subjects out of 10, the predictability during sleep is better than during the daytime.     

Design of a modulo p multiplier

Some basic problems on the design of multiple-valued circuits are discussed on the basis of a modulo 5 full-multiplier. It is shown that appropriate transformations at the highest abstraction level may reduce some design constraints. In the case of the mod 5 multiplier, it is possible to alleviate linear dynamics range demands. Moreover it is shown that multiple-valued design may offer some space-time trade-offs with respect to binary.     

EFFECT OF ANTEMORTEM JOURNEY AND LAIRAGE AT ABATTOIR ON RABBIT MEAT QUALITY

A study was conducted to determine the effects of journey duration (1 versus 3 h) and lairage time at abattoir (0 versus 5 h) on rabbit meat quality traits. Rabbits transported for 3 h produced meat with significantly higher pH values ( P <  0.01), darker (lower L* values, P <  0.01) and less yellow ( P <  0.05) color, as well as lower losses during cooking ( P <  0.01), than those transported for 1 h. Moreover, animals laired for 5 h yielded meat with more ( P <  0.05) yellow color, cooking losses ( P <  0.05) and higher shear values ( P <  0.01) than rabbits not laired before slaughtering. The nuclear magnetic resonance analysis revealed that these differences ( P <  0.05) are mainly related to changes occurring in the distribution of myofibrillar (T₂₁) and extra-myofibrillar (T₂₂) water. In conclusion, this study indicated that journey time and lairage at abattoir may play an important role in determining rabbit meat quality traits.

PRACTICAL APPLICATIONS

In many previous studies that considered the effect of journey and lairage on rabbit meat quality, animals were stress-induced by extreme conditions of journey and/or lairage that were unlikely to occur during commercial operations. The aim of this study is to establish whether meat quality characteristics are still influenced when journey and lairage times match current commercial production practices. Because processing-plant efficiency depends on product uniformity, it will be interesting to test the potential variability effect of rabbit preslaughter practices on meat quality properties.