Different parameters affecting lipid oxidation in meatballs

Abstract

The aim of this master thesis was to produce meatballs with different characteristics and from these, find the meatball that oxidized the most. For the production, minced meat with different concentrations of salt and fat from both beef and pork was used. Half of the meatballs were pan-fried and the other half was deep fat fried. Additionally, three different storage times were applied. The meatballs with most lipid oxidation were produced again, this time with antioxidants added to them.

The type of meat and storage time had the largest impact on lipid oxidation. While salt concentration and cooking method had moderate affect. The fat content did not significantly affect the level of lipid oxidation when comparing the TBAR values per g meatball. It was concluded that pork meatballs were more prone to oxidize than beef, most likely due to the higher amount of unsaturated fat and lesser fat loss. With longer storage time, more lipid oxidation can take place.

Adding antioxidants to the meatballs decreased lipid oxidation. The oxidation decreased more with higher concentrations of polyphenols of which OPP had a greater affect than oregano oil. This points to that the composition of polyphenols in OPP could be better for inhibiting oxidation since they showed a better antioxidative capacity. The lipid oxidation decreased more in pork than in beef.

In the sensory analysis, the panellists experienced the beef meatballs to be more compact than pork. This can be correlated to the higher total weight loss for beef meatballs. A consequence of lipid oxidation is the creation of rancid off-flavour. However, this relation was not detected by the panellists.

Popular Abstract

Preserving meat quality with natural antioxidants
They are powerful, they are excellent cleansers and they are honoured in all fitness and health magazines. A lot of hype surrounds this group off “super foods” called antioxidants! What are these compounds and can they preserve meat quality?

Let us start with what antioxidants are and what they can do. Antioxidants do what their name suggests, they prevent oxidation. Oxidation is a process that can take place in meat when oxygen reacts with iron, creating reactive ions. These ions can oxidize unsaturated fat in the meat and, as a consequence, create a rancid off-flavour and decreased shelf-life. A more commonly known form of oxidation is when these reactive ions oxidize metals on your car, creating rust. An antioxidant works as a neutralizer and counterbalances the reactive ions, preserving the meat.

The first part of this project was to find a processed meat product especially susceptible to oxidation. In Sweden, meatballs are considered to be a national dish and are thus consumed in high amounts by the Swedish population. Therefore, the meatball was chosen in this project to find the type of meatball that oxidizes the most. This was done by producing different kinds of meatballs containing different types of meat, amounts of fat and salt. Half of the meatballs were made of pork and the other half of beef. Pork has more unsaturated fat than beef and therefore oxidized more. After the meatballs were cooked, they were stored in the fridge for different amounts of time. The meatballs that were stored the longest time had more oxidized fat, which was not a surprise. If you prepare food and keep it in the fridge for one day it still tastes good. But if you forget your meat and try to eat it after two weeks it can taste very bad. This is mainly due to fat oxidation.

Now back to the antioxidants. Antioxidants can be found in berries, fruits and vegetables, but also in spices. In the frame of this project two different antioxidants, from olives and oregano, were added to the meatballs. This addition resulted in a substantial decrease in fat oxidation. It can be concluded that the olive antioxidants were better at taking care of the reactive ions than oregano.

Fat oxidation in meat is a major problem for the food industry. It causes deterioration of quality, with rancidity and a decrease in shelf life as two big problems. Meat is responsible for 29 % of the food waste generated from Swedish supermarkets. When adding natural antioxidants the quality of the meat and the shelf life increases. It is a win-win situation, both for your wallet and for the environment.

Many studies show that there is a relation between a high intake of processed meat and increased risk of colorectal cancer. Some suggest that this can be due to the oxidation process in the meat. Maybe, one day, it can be proven that by adding antioxidants to the meat, it gets healthier and the risk of causing cancer decreases.

• author: Granheimer, Kajsa
• supervisor: Stina Burri; Eva Tornberg
• organization: Food Technology and Nutrition (M.Sc.)
• course: KLT920 20171
• year: 2017
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering; Agriculture and Food Sciences
• language: English
• id: 8912102
• date added to LUP: 2017-06-13 17:26:06
• date last changed: 2017-06-13 17:26:06