QUALITY AND SWEETNESS OF BAKED CUSTARDS MADE WITH LACTOSE-REDUCED MILKS

Lactose concentrations of lactose-reduced and hydrolyzed lactose-reduced milk (12.1, 4.9 g/L milk, respectively) were significantly lower (p < .05) than the lactose concentration in the control (1% milkfat) milk (38.4 g/L milk). Lactose concentrations in custard mixes made from lactose-reduced and hydrolyzed lactose-reduced milks (6.8, 3.2 g/L mix, respectively) were significantly lower (p < .05) than the lactose concentration in the control custard mix made from 1% milk (29.9 g/L mix). Consumers ranked the lactose-reduced milk and the hydrolyzed lactose-reduced milk significantly higher in sweetness than the control milk. No differences in sweetness between the control, lactose-reduced, and hydrolyzed lactose-reduced baked custards were perceived. Firmness, color, syneresis, and water activity did not differ (p > .05) among the control, lactose-reduced, and hydrolyzed lactose-reduced baked custards.     

Histological analysis of pollen-pistil interactions in sour passion fruit plants (Passiflora edulis Sims)

The success of sexual plant reproduction is directly influenced by specific interactions between the pollen and pistil. Light, fluorescence and scanning electron microscopy techniques were used to evaluate the steps of pollination in sour passion fruit plants (Passiflora edulis Sims). In the compatible interaction, pollen tubes grow through stigma projections towards the ovary. The pollen grain surface was found to be spheroidal and to consist of heteroreticulate exine with six colpi. Furthermore, analysis in vivo of pollenpistil interactions indicated that stigmas of flowers 24 hours before anthesis are unable to discriminate compatible (genetically unrelated) and incompatible (genetically related) pollen grains. Taken together, these results provide insight into the cellular mechanisms underlying pollination in passion fruit plants.     

SHAPE OPTIMIZATION IN SHELL THEORY: Design Sensitivity of the Continuous Problem

We consider a non-shallow shell made of an isotropic homogeneous material, working in linear elastic conditions, subjected to a given load. Our aim is to change the shape of the shell so that it resists better towards a given criterion. By shape, we mean essentially the midsurface of the shell. The thickness could be added without any difficulty. The important aspect that we study here is the midsurface.

This problem is worked by gradient type methods. We prove that if the criterion depends on the displacement field through a differentiable function, then it depends on the shape in a differentiable manner, because the displacement field is a differentiable function of the shape. Then we present an analytical formula giving the exact gradient of the criteria before any discretization. After that, we explain how to compute numerically an approximation to this exact gradient. Then we give numerical results.     

EFFECTS OF PROLINE AND PROLINE ANALOGS ON TOTAL PHENOLIC AND ROSMARINIC ACID LEVELS IN SHOOT CLONES OF THYME (Thymus vulgaris L.)

Plant phenolic compounds such as rosmarinic acid exhibit antioxidant and antimicrobial activities and have potential as functional food ingredients. Our model has proposed that a cellular redox cycle linking pyroline-5-carboxylate and proline can stimulate the pentose phosphate, shikimate and phenylpropanoid pathways, and ultimately lead to an increase in phenolic synthesis, including rosmarinic acid (RA). In this study, the response of thyme shoot clones to proline and/or proline analogs was investigated through measurement of total phenolics, rosmarinic acid and proline levels, as well as glucose-6-phosphate dehydrogenase (G6PDH) and phenylalanine ammonia-lyase (PAL) activities. A genetically uniform, high phenolic-containing thyme shoot-based clonal line T-12 was used. Results indicate that supplementation of exogenous proline did not enhance total phenolic and rosmarinic acid content. Therefore, exogenous proline may not have stimulated the proline-linked pentose phosphate pathway. However, increases in proline, total phenolics and rosmarinic acid synthesis were observed following supplementation with the proline analogs, hydroxyproline and azetidine-2-carboxylate. These analogs through proline synthesis may have activated the pentose phosphate pathway and therefore the phenylpropanoid pathway by linking steps involved in NADP/NADPH interconversions. As a result, increases in total phenolic and rosmarinic acid levels were observed. This mode of regulation via proline synthesis-linked to pentose phosphate pathway may be important for synthesis of RA and its overexpression in elite thyme clonal lines for food and medicinal applications.     

PSEUDOMONAS SPP.-MEDIATED REGULATION OF TOTAL PHENOLIC AND ROSMARINIC ACID LEVELS IN SHOOT-BASED CLONAL LINES OF THYME (THYMUS VULGARIS L.)

Plant phenolics are secondary plant products, sometimes synthesized as chemical defenses to microorganisms, and also serve as potential sources of food preservatives. In this study, we have investigated the extent of stimulation of total phenolics and rosmarinic acid (RA) levels in three in vitro shoot culture-based thyme clonal lines in response to a novel Pseudomonas spp. previously isolated from oregano tissue cultures. Clonal lines chosen for this study were the high phenolic line T-12 and the medium- and low-phenolic lines T-16G and M-3. Results indicate that different strains of Pseudomonas stimulated total phenolic levels and RA accumulation to varying degrees. Mucoid strain M4 elicited the highest levels of RA in clonal line T-12 on day 25. A moderate degree of RA stimulation in response to M4 was observed in clonal line M-3. Mucoid strain F elicited the highest total phenolic levels in T-12 on day 25. Nonmucoid strain NMA elicited stimulation of total phenolic compounds and RA to some degree only in clonal line T-16G. A 30 day time course analysis in line T-12 indicated that strains F and NMA elicited the highest phenolic levels. RA synthesis appeared to be stimulated in response to M4 at later stages of growth and reduced stimulation was apparent in response to F and NMA. The mechanical rigidity of T-12 shoots appeared to be highest in response to mucoid strain M4, indicating the possibility of increased lignin formation. This Pseudomonas-thyme clonal system provides a foundation to investigate the microbially-elicited stimulation of biosynthetic pathways leading to novel antimicrobials and antioxidants.     

Time-Intensity Study of Prolonged Sweet Stimuli

Prolonged intensity and hedonic (like/dislike) temporal responses and any associated adaptive behavior toward various sweet solutions (sucrose in water) were investigated with specific focus on factors that influenced the transition from “like” to “dislike”. Subjects evaluated the samples using computerized time-intensity (T-I) methods to produce sweetness intensity-time and like/dislike-time response curves. The higher concentration solutions resulted in adaptive behavior. Also, like-to-dislike transition times correlated with sucrose concentration, as did other defined parameters which characterized aspects of the responses, several of which displayed significant cross correlations.     

Functional Properties of Enzymatically Modified Beef Heart Protein

The effect of enzymatic modification on beef heart protein functionality was examined in model system and frankfurter experiments. Modification of heart myofibrils with ficin was effective in improving protein solubility and emulsification capacity compared to controls. Incorporation of enzyme-modified heart into a meat model system composed of 30% beef heart and 70% beef skeletal meat resulted in improved cooked yields which were equal to controls made with 100% skeletal meat, in both no-salt and 3% salt formulations. Normal (2%) and low (0.5%) salt frankfurters made with 30% enzyme-modified beef heart had significantly greater smokehouse yields and consumer cooked yields than frankfurters made with 30% unmodified heart.     

Lactate Dehydrogenase Monoclonal Antibody Immunoassay for Detection of Turkey Meat in Beef and Pork

Relative epitope binding positions on turkey muscle LDH of four monoclonal antibodies (MAbs) was determined by comparing the absorbance by sandwich ELISA from different combinations of capture and biotinlabeled detector MAbs. Epitopes for MAbs E6B and B3C were close to each other. Binding of MAb B3C and G4D did not inhibit binding of D5E to LDH, thus a sandwich ELISA using D5E as capture MAb, and biotin-labeled B3C as detector MAb was developed. The LDH MAb sandwich ELISA detected 1% adulteration of turkey breast or thigh muscle in raw beef and pork.