Suppression of the cysteine protease, aleurain, delays floret senescence in Brassica oleracea

An aleurain-like protein, BoCP5, is up-regulated during harvest-induced senescence in broccoli floret and leaf tissue. BoCP5 is most closely related to an Arabidopsis protein (91%, AAF43041) and has 71% identity to barley aleurain (P05167). The mRNA for this gene accumulates within 6 h after harvest in broccoli florets, and its expression is reduced in tissue that has been held in senescence-delaying treatments (e.g. water, sucrose feeding, controlled atmosphere). The gene is also expressed in leaves during aging-related and harvest-induced senescence. Analysis of protein bands that cross-react with antibodies raised to the bacterial BoCP5 fusion protein, revealed prominent immunoreactive bands at ca. 26, 28, 31, and 38 kD in floret tissue. The 31 kD band was absent in protein extracts from leaf tissue. Agrobacterium-mediated transformation was used to produce transgenic broccoli plants with down-regulated BoCP5. A reduction in the postharvest expression of BoCP5 in floret tissue was achieved for four transgenic lines in the current study. In three of these lines postharvest floret senescence (yellowing) was delayed, and florets contained significantly greater chlorophyll levels during postharvest storage at 20 degrees C than wild-type plants. Line 4 showed the greatest down-regulation of BoCP5, and in this line postharvest protease activity remained at pre-harvest levels, and the yield of soluble proteins extracted from florets after harvest was significantly greater than that of wild-type tissue.

Comparison of four different backpacks intended for school use

Four backpacks were evaluated for their desireability for use as school bags. Three of the four backpacks were specifically designed for school use based on previous research and ergonomic principles while the fourth (standard) backpack was chosen from two backpacks that their manufacturer considered to be the most likely to be used as a school bag. Twelve school students evaluated each of the backpacks firstly by examining them, again after donning them and again after walking with them on a treadmill by completing a questionnaire asking about the appearance, function and comfort of each backpack. On initial examination, the standard backpack was the most favoured but as functionality became increasingly important during the treadmill walk, the backpack which was designed specifically for school use and had two major compartments, substantial back padding and side compression straps became the most favoured. This particular design of backpack was reported as having the greatest practicality, being the least physically demanding and allowing the greatest balance and ease of walking. The results of this study suggest that school student's preference of backpack may change from when they first examine a prospective backpack to when they have used it. The study also shows that school students' preferred attributes in a backpack may shift over this time from 'style and image' to 'function and fit'.

Sensory and hedonic judgments of common foods by lean consumers and consumers with obesity

OBJECTIVE

To establish differences between lean subjects and subjects with obesity in subjective reports of predominant taste and texture attributes of common foods, and the relationships of these qualities and foods with overall liking.

RESEARCH METHODS AND PROCEDURES

Twenty lean (body mass index: 20 to 25 kg/m2) nondieting healthy adults and 23 (body mass index: > or = 30 kg/m2) nondieting healthy adults with obesity assigned ratings for pleasantness and predominant sensory attributes to 50 common foods in 14 food groups using a questionnaire. They completed the Dutch Eating Behavior Questionnaire. Body composition was assessed by bioelectrical impedance.

RESULTS

There were no significant group differences between pleasantness scores overall; however, lean subjects assigned higher scores to fruits and vegetables, to foods self-classified as sweet and as salty/savory, and to foods grouped in the highest and lowest quintiles of percentage food energy from fat. There were no group differences in free-choice texture descriptors applied to foods, but correspondence analysis revealed that subjects with obesity associated coarse, slippery, tough, and fatty textures with "dislike extremely," whereas lean subjects associated grainy, moist, doughy, and fibrous texture with "like extremely." Analyses reduced texture terms to 39 key descriptors for use in subsequent work. Groups did not significantly differ in reported external or restrained eating behaviors, but subjects with obesity scored significantly higher for reported emotional eating.

DISCUSSION

Differences in preferences for listed common foods exist between weight status groups according to taste, food group, and texture. Consumers can make textural descriptions of foods that could be used to assess sensory and hedonic qualities of actual food choices.

Methodological approaches to assessing risk perceptions associated with food-related hazards

The psychometric approach developed by Slovic and his co-workers has been effectively used to assess risk perceptions associated with different food-related hazards. However, further examination (using questionnaire data and partial correlation techniques) has indicated that technological hazards are highly differentiated from lifestyle hazards, in terms of both hazard control and knowledge about the hazard. Optimistic bias was also seen to vary between hazards. Further research has focused on a particular hazard, genetic engineering. Risk perceptions associated with genetic engineering are underpinned by ethical concern and questions relating to perceived need for the technology, as well as perceptions of risk or harm. However, increasing the specificity of hazard stimuli was found to alter the factor structure of underlying risk perceptions. The utility of preference mapping procedures in determining individual differences in trust in risk regulators is also discussed.

The elaboration likelihood model and communication about food risks

Factors such as hazard type and source credibility have been identified as important in the establishment of effective strategies for risk communication. The elaboration likelihood model was adapted to investigate the potential impact of hazard type, information source, and persuasive content of information on individual engagement in elaborative, or thoughtful, cognitions about risk messages. One hundred sixty respondents were allocated to one of eight experimental groups, and the effects of source credibility, persuasive content of information and hazard type were systematically varied. The impact of the different factors on beliefs about the information and elaborative processing examined. Low credibility was particularly important in reducing risk perceptions, although persuasive content and hazard type were also influential in determining whether elaborative processing occurred.

What determines trust in information about food-related risks? Underlying psychological constructs

Trust in risk information about food related-hazards may be an important determinant of public reactions to risk information. One of the central questions addressed by the risk communication literature is why some individuals and organizations are trusted as sources of risk information and others are not. Industry and government often lack public trust, whereas other sources (for example, consumer organizations, the quality media, medical doctors) are highly trusted. Problematically, previous surveys and questionnaire studies have utilized questions generated by the investigators themselves to assess public perceptions of trust in different sources. Furthermore, no account of the hazard domain was made. In the first study reported here, semistructured interviewing was used to elicit underpinning constructs determining trust and distrust in different sources providing food-related risk information (n = 35). In the second study, the repertory grid method was used to elicit the terminology that respondents use to distinguish between different potential food-related information sources (n = 35), the data being submitted to generalised Procrustes analysis. The results of the two studies were combined and validated in survey research (n = 888) where factor analysis indicated that knowledge in itself does not lead to trust, but that trusted sources are seen to be characterised by multiple positive attributes. Contrary to previous research, complete freedom does not lead to trust-rather sources which possess moderate accountability are seen to be the most trusted.

Effect of effort on meal selection and meal acceptability in a student cafeteria

Past laboratory and field studies show that the effort necessary to obtain food acts as a determinant of food selection and consumption. Two studies examined the impact of increasing the effort needed to obtain candy or potato chips on selection in a normal lunch setting. In the first study, food selection, acceptance and intake were obtained during the first week baseline and under the effort manipulation during the second week. With increased effort, candy selection dropped dramatically in week 2. Subjects substituted items from the desert, fruit and accessory food groups. In the second study, food selection and acceptance were measured during a 2-week baseline, a 3-week effort period, and a 3-week recovery period. With increased effort, potato chip selection dropped dramatically and only partially recovered in the last phase. Subjects substituted items from the starch food group. These results demonstrate that changes in the effort needed to obtain food can have a nutritional impact in an actual eating situation and could be an important part of a healthy eating strategy.