/library/oar/handle/123456789/8432 2026-05-28T03:57:02Z /library/oar/handle/123456789/15748 Title: Ultrasound technology for controlling the food safety and quality of fresh produce Abstract: Fresh produce contain bioactive compounds with diverse beneficial health effects. Due to the consumers’ awareness about these health benefits, consumption of fresh produce has increased. However, this has been accompanied by an increase in food-borne illnesses since fresh produce, apart from having a relatively short shelf-life; it also favours the growth of pathogenic food-borne microorganisms. Thus, the demand for novel technologies that enhance food safety of fresh produce has increased with time. Furthermore, consumers also demand the use of methods that avoid the use of chemicals and have a lower impact on the nutritional content and quality of food. The objective of this research was to assess the effect of ultrasound as an alternative decontamination technology on selective chemical (peroxidase, POD and pectin methylesterase, PME enzymes) and nutritional (polyphenols and vitamin C) properties of Romaine lettuce and yellow bell pepper. For this purpose a number of different experimental protocols were assessed and further improved to achieve reproducible and accurate measurements of these chemical and nutritional indices following the application of ultrasound. This was implemented so as to decide on the optimal ultrasound treatment parameters whereby the quality of the fresh produce was not affected if it had to be used as an alternative decontamination technology. PME and POD were present at a low concentration in yellow bell peppers. In lettuce, the most effective treatment to reduce PME activity was US 5 min continuous while in the case of POD, none of the applied ultrasound treatments significantly reduced POD activity. All ultrasound treatments reduced the total polyphenol content in lettuce, therefore, it can be concluded that the investigated ultrasound processes are not suitable to treat lettuce in terms of their effect on total polyphenol concentration. In bell peppers, the ultrasound process which caused the least reduction was ultrasound applied for 5 min continuous. Vitamin C in lettuce appeared to be present in insignificant levels. In bell peppers, the ultrasound process which caused the least degradation of vitamin C was ultrasound applied for 5 min continuous. When considering all the four analysed food quality indices, in the case of bell peppers, ultrasound applied for 5 min continuous was the best process since it caused the least reduction in both polyphenol content and vitamin C. However, in the case of lettuce, further research is required related to the application of ultrasound treatment since, only in the case of PME, conclusive results were obtained in favour of ultrasound application. It can be concluded that ultrasound is a decontamination technology that has the potential to be implemented in the fresh produce industry and needs to be further investigated with respect to different food products and a number of critical quality indices. Description: M.SC.FOOD STUD.&ENV.HEALTH 2015-01-01T00:00:00Z /library/oar/handle/123456789/8933 Title: The cost implications of a healthy diet Abstract: A balanced diet is an essential aspect of a healthy lifestyle. The cost of healthy food may affect consumer purchase. The aim of this study was to compare the prices of healthy and less healthy foods in Maltese supermarkets and to determine whether the former are really more expensive. A list of 102 foods, consisting of 51 healthy foods and their unhealthier counterparts were selected from the literature and also taking the Healthy Eating Index – 2010 into consideration. Food price data was collected from five supermarkets across the five geographical districts of Malta in order to ensure a representative sample. Foods were classified into distinct food groups and the Mann-Whitney non-parametric test was carried out to test for price differences between healthy and less healthy foods in each group. An overall analysis of the price differences was done using an unpaired t-test. The mean price was €0.63/100g (±0.55) and €0.60/100g (±0.362) for healthy and less healthy food respectively. Thus, there was a small, statistically insignificant price difference. There were differences in the distinct food groups, with healthy grains, protein sources, dairy products and miscellaneous food items being more expensive per 100g than the unhealthier groups. Such differences were statistically insignificant. Fruits and vegetables were significantly cheaper than processed food by €0.40/100g (p=0.034). In view of the fact that specific healthy items in some groups were more expensive than others compared to the less healthy items and vice versa, the overall price difference was statistically insignificant. This study therefore suggests that the cost barriers of consuming healthy foods are not insurmountable, implying that it is possible to include lower cost healthy food such as nuts, legumes, reduced fat dairy and fruits and vegetables in favour of the higher priced lean meats and processed food. Description: B.SC.APPLIED FOOD&NUTR. 2015-01-01T00:00:00Z