Monola oil versus canola oil as a fish oil replacer in rainbow trout feeds: effects on growth, fatty acid metabolism and final eating quality

Monola oil, a high oleic acid canola cultivar, and canola oil were evaluated as replacers of 26 fish oil at three levels of inclusion (60, 75 and 90%) in rainbow trout diets. After a 27-week 27 grow-out cycle, the diet-induced effects on growth, fatty acid metabolism and final eating 28 quality were assessed. Overall, no effects were noted for growth, feed utilisation or fish 29 biometry, and the fatty acid composition of fish fillets mirrored that of the diets. Dietary 30 treatments affected fillet lipid oxidation (free malondialdehyde), pigmentation and flavour 31 volatile compounds, but only minor effects on sensorial attributes were detected. 32 Ultimately, both oils were demonstrated to possess, to differing extents, suitable qualities 33 to adequately replace fish oil from the perspective of fish performance and final product 34 quality. However, further research is required to alleviate on-going issues associated with 35 the loss of health promoting attributes (n-3 long chain polyunsaturated fatty acids) of final 36 farmed products

The relationship betwen NaCl concentration and taste perception of saltiness in bread

Background &ndash; Sodium (Na+ ) is present in food in the form of sodium chloride (NaCl). There is strong evidence that high dietary Na+ intakes increase the risk of developing various adverse health conditions. Many international organisations encourage Na+ reduction in both the diet and the food supply. One of the major dietary sources of NaCl is bread, where NaCl has the essential function of imparting flavour. At present, no literature has been published examining taste interactions that may play a role in limiting the maximum saltiness perception in bread.Objective &ndash; To determine the extent the physical structure of bread inhibits salty taste perception. Additionally, to determine whether common commercial bread additives suppress saltiness of bread.Design &ndash; Subjects (n=14, 12 females) tasted and rated samples with varying NaCl concentrations in water (0 &ndash; 1724 mg NaCl/100 g) and bread (125 &ndash; 1550 mg NaCl/100 g) using the general Labelled Magnitude Scale. Psychophysical curves plotting NaCl concentration against NaCl intensity were constructed for water and bread. Breads of fixed NaCl concentration (1125 mg NaCl/100 g) and various common additives (sucrose, soya flour, canola oil, gluten) were also rated to assess perceived saltiness.Outcomes &ndash; There was a significant difference between Na+ psychophysical curves in water and bread (P&lt;0.05) with the bread matrix suppressing maximum possible saltiness by 25% to 70%. Suppression of saltiness was observed after the addition of sucrose (55% decrease) or soya flour (60% decrease) during bread production compared to prototypical bread (both P&lt;0.05).Conclusions &ndash; The physical structure of bread and some common additives have a major influence on perceptual saltiness of bread. The removal of additives that suppress saltiness combined with strategies to modify the texture of bread could lead to significant reduction in dietary Na+, whilst maintaining optimal salty taste.<br /

Taste sensitivity to NaCl is associated with liking of salty foods and BMI

Background &ndash; It is widely acknowledged that sodium is consumed in excess in most developed countries. Sodium (Na) consumption has been a target of public health interventions in recent years due to its link to numerous adverse health affects such as hypertension and cardiovascular disease. While much of the current research is directed at strategies to reduce sodium in foods and the diet, little is known about the factors which determine salt consumption and preference. Currently, there is no research relating NaCl taste sensitivity and liking of food, or if NaCl taste sensitivity may manifest in changes in BMI.Objective &ndash; Establish whether a relationship exists between NaCl taste sensitivity, preference for salty foods and BMI.Design &ndash; Taste sensitivity to NaCl was determined for 119 subjects (104 female) according to the procedure laid out by &ldquo;ISO 3972:1991 &ndash; Method of investigating sensitivity of taste&rdquo;. In a separate session subjects rated their liking of generic biscuit with 2 levels of added NaCl [low (2.9g/100g) &amp; high (19.1g/100g)] using the 9-point hedonic scale. BMI was calculated from self reported height and weight data collected. Spearman&rsquo;s rank order correlation was used to determine whether an association existed between NaCl taste sensitivity, preference for salty foods and BMI.Outcomes &ndash; A significant positive correlation was found between BMI and NaCl taste sensitivity (r=0.204, p&lt;0.05). In addition there was a significant positive correlation between BMI and liking of low NaCl biscuits (r=0.267, p&lt;0.01). No significant associations were identified between the high NaCl cracker and NaCl taste sensitivity or BMI. A paired t-test showed there was no significant difference in liking of the low and commercial NaCl crackers (p=0.078).Conclusion &ndash; This study revealed that individuals with a higher BMI have a greater liking of low NaCl biscuits, and this may be due to their increased NaCl taste sensitivity. The results suggest that NaCl taste sensitivity may be a factor in foods consumed by an individual which in turn may influence weight status.<br /

The role of fatty acids in satiation and satiety

Background &ndash; Satiation and satiety describe the events which lead to meal termination and the maintenance of hunger induced by physical and metabolic events following food ingestion. Fatty acids, components of dietary fat (triglyceride) may be important, if not essential components of satiation and satiety. Emerging evidence suggests fatty acid now constitutes a sixth taste modality and orally sensed fatty acids mediate unique cephalic and hormonal responses priming the body for fat digestion, and may contribute to sensory specific satiety. Once ingested, fatty acids are sensed in the gastrointestinal tract (GIT) where they cause the release of hormones, stimulate the vagus and enter the blood stream where they act a number of organs (brain, liver) to influence satiety.Objective &ndash; To review the role of fatty acids in sensory and metabolic satiation and satiety.Design &ndash; Literature search and review of papers from the past decade on satiety, satiation, fat taste and fatty acids.Outcomes &ndash; The physiological significance of gustatory fat detection is still unclear, but it may signal the nutritious content of fat similar to the tastes of sweet or umami which signal the presence of carbohydrate or proteins. Like other tastants, fatty acid taste sensitivity is thought to vary in the population and differences in sensitivity may influence dietary choice and fat intake. Fatty acid taste may contribute to sensory specific satiety as foods are eaten. Animal models have observed an inverse relationship between oral fatty acid sensitivity and fat consumption, which leads to obesity. Observations that the obese have heightened preferences for, and consume more fat than lean individuals questions whether such a relationship may also be apparent in humans. At the GIT, fatty acids are sensed by enterocytes and bind to receptors, transporters or ion channels where they initiate gut-brain communication over nutrient status through the vagus and cause the release of satiety hormones which lead to meal termination. Inefficient fatty acid sensing at either or both locations is thought to accompany the aetiology of obesity.Conclusion &ndash; Variations in sensitivity to fatty acids may alter preferences and consumption of fats or hormonal responses to fat ingestion which influence sensory-specific, metabolic and subjective satiety.<br /

Short communication: Influence of labeling on Australian and Chinese consumers\u27 liking of milk with short (pasteurized) and long (UHT) shelf life

Sixty percent of milk consumed in China has a long shelf life (UHT), presumably because milk with a short shelf life (pasteurized) is comparatively expensive. This in contrast to Australia, where 10% of consumed milk is UHT and the price between UHT and pasteurized milk is equivalent. Whether UHT is actually more liked than pasteurized milk by Chinese consumers is unknown. However, the potential positive halo around the expensive pasteurized milk might result in Chinese consumers liking milk more when it is labeled as &quot;short shelf-life milk.&quot; To test these hypotheses, Chinese (n=48, 20 males, 28 females, 23&plusmn;7.2 yr) and Australian (n=93, 11 males, 82 females, 24&plusmn;5.6 yr) consumers tasted and rated (9-point hedonic scale), in a randomized order, 3&times;30-mL samples of UHT milk (labeled as &quot;long shelf-life milk,&quot; &quot;short shelf-life milk,&quot; or &quot;milk&quot;) and 3&times;30-mL samples of pasteurized milk (also labeled as &quot;long shelf-life milk,&quot; &quot;short shelf-life milk,&quot; or &quot;milk&quot;). Australian participants\u27 liking of milk was not influenced by labeling. Regardless of what the label stated, they always preferred the taste of pasteurized milk over the taste of UHT milk. This was different for Chinese participants, who preferred the taste of UHT milk over the taste of pasteurized milk, but in general had a higher liking for any milk that was labeled &quot;short shelf-life milk.&quot; Both Australian and Chinese were more positive about pasteurized than UHT milk. In conclusion, Chinese, but not Australian, consumers\u27 liking of milk was guided by the positive expectations of pasteurized milk and the negative expectations of UHT milk. Further research is needed to investigate if the present findings can be extrapolated to a larger and more varied group of Chinese and Australian consumers