Detta arbete undersöker förhållandet mellan kvalitetsparametrar i frityrolja, såsom halten fria fettsyror (FFA), anisidinvärdet (AV) och %TPM (Total Polar Materials) samt Agtronvärdet hos köttbullar efter fritering. Kvalitetsparametrar hos frityrolja, såsom primära och sekundära oxidationsprodukter, kan mätas för att utvärdera oljans kvalitet då nivåerna ofta ökar i samband med oljans användning. Primära oxidationsprodukter, såsom peroxider, kan mätas med hjälp av ett så kallat peroxidvärde (PV) och sekundära oxidationsprodukter, såsom aldehyder, kan mätas med hjälp av anisidinvärdet. Analys av %TPM och FFA är exempel på andra metoder för att mäta kvaliteten hos en olja då polariteten ökar i takt med oljans användning. Halten FFA i oljan undersöktes med hjälp av titrering med natriumhydroxid och %TPM mättes med hjälp av mätinstrumentet Testo 270. Agtronvärdet hos köttbullarna mättes med hjälp av instrumentet Agtron E30FP, som använder IR-teknologi för att bestämma färgen på en produkt. Resultaten visade att halten FFA, AV och %TPM i frityroljan ökade med tiden under samtliga fyra produktionsdagar. Hypotesen att produkten bör vara mörkare, det vill säga att Agtronvärdet bör vara lägre vid produktionens slut jämfört med början stödjs av resultaten från två av fyra produktionsdagar. Slutsatsen drogs att det fanns skillnader i oljans sammansättning, med hänsyn till FFA, AV och %TPM vid produktionsdagens slut jämfört med start. Däremot kunde ingen tydlig koppling ses mellan dessa förändringar och en minskning av Agtronvärdet hos köttbullarna över tiden. Ytterligare studier behövs således för att kunna dra en slutsats kring sambandet mellan kvalitetsparametrar i frityrolja och färgen på det friterade livsmedlet. / This study examines the relationship between quality parameters of frying oil, such as Free fatty acids (FFA), the Anisidine Value (AV) and Total Polar Materials (%TPM), as well as the Agtron Value of meatballs after deep frying. Quality parameters in frying oil, such as primary and secondary oxidation products, measure the quality of the frying oil since levels increase with the use of the oil. Primary oxidation products, such as peroxides, can be measured by the Peroxide Value (PV) and secondary oxidation products, such as aldehydes, can be measured by the Anisidine Value. Analysis of %TPM and FFA are other methods to measure the quality of an oil, since the polarity increases as the oil is used for frying. The instrument Testo 270 was used to measure %TPM in the oil and FFA was determined by titration with sodium hydroxide. The Agtron E30FP instrument was used to determine the Agtron Values of the meatballs, wich used IR technology to determine the color of the product. Results showed that the FFA, AV and %TPM of the oil increased over time in all four production days. It was expected that the product should be darker, that is, the Agtron Value should be lower at the end of production compared to the beginning, but this was only seen in two out of four production days. It was concluded that there are differences in the composition of the oil, with regard to FFA, AV and %TPM at the end of the production day compared to the beginning of the day, but no clear connection was seen between these changes and a decrease in the Agtron Value of the meatballs over time. Further studies are needed to be able to draw a conclusion about the relationship between quality parameters of frying oil and the color of the fried food.

Oxidation limits the shelf life of many food products. Adding antioxidants to foods is the most common way to solve this problem. Reports on safety issues of synthetic food additives have raised consumer interest in "all natural" foods, without added antioxidants or with synthetic replaced with natural antioxidants. The natural antioxidants now in use are much more expensive and less potent than the synthetic antioxidants. Thus, effective and economical natural antioxidants are of great interest to researchers. Teng Cha is a type of herbal tea found in China that has reported high levels of antioxidants. Antioxidant activity of Teng Cha extract and its major component dihydromyricetin has been reported, but no studies have provided clear evidence for the antioxidant effectiveness of Tech Cha extracts. The goal of this study was to measure the antioxidant activity of Teng Cha extract and dihydromyricetin (DHM), a major component of Tech Cha extract. The DPPH assay was conducted and antioxidant activities of the crude extract and dihydromyricetin were evaluated in soybean oil based on the peroxide value, anisidine value, Totox value, headspace volatiles and headspace oxygen. Antioxidant effectiveness was also evaluated in a cooked beef model system. DHM was more potent than BHA in preventing soybean oil oxidation. The crude extract was not as effective as BHA and DHM, possibly because it contained transition metals. In cooked beef, DHM and the crude extract showed lower activity than BHA, possibly due to their low solubility. Overall, Teng Cha extract and DHM are potential natural food antioxidants for future applications. / Master of Science in Life Sciences