Essay about Study of Effect of Sodium Nitrite on th

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Study of Effect of Sodium Nitrite on the Color of Cured Beef

Instructor: Bruce Xu
Participators:
Zhang Xinwen
Sheng Huizhong

Report written by:
Zhang Xinwen
1131300048
Signature:

Experiment Data: 29th September, 2014
Handing Data: 6th October, 2014
Study of Effect of Sodium Nitrite on the Color of Cured Beef

Abstract
The appearance and taste of meat is an important component of consumer acceptance. Color is the most important quality indicator used by consumers to judge meat freshness. Sodium nitrite is usually used as food additive in meat products, which can develop pink color, inhibit the growth of food spoilage bacteria, and contribute to the favor and the texture. This experiment was going to use sodium nitrite to treat the raw fresh beef, in order to study the effect and function of sodium nitrite in meat curing. The result showed that the meat will become brown just after the sodium nitrite was added but turned back to a desirable red color after preserve in the fridge overnight and showed a pink color after cook. The control sample which did not add sodium nitrite was red at the beginning but the surface was turning brown after stored in the fridge overnight and also turned to deep brown after cooked.

Introduction
Fresh meat preservation is really important for butcher, because color is the first thing that the consumer uses to judge the freshness of meat. At the same time, the customer in the restaurant will also judge the freshness of meat by color and the color of the meat will affect their appetite directly. If the color of the meat was pale or darkness, the consumer would not like to buy it anymore, so keeping the fresh and original color of meat is very important for meat selling. The fresh beef color which just after slaughter is a deep purplish. When the meat was exposed to oxygen for a period of time, the oxygen is absorbed then combines with myoglobin which produces brighter color pigment which called oxymyoglobin. Myoglobin and oxymyoglobin have the capacity to oxidize, which turns the pigment to a brown color called metmyoglobin. Myoglobin, oxymyoglobin, and metmyoglobin can all be changed from one to the other when the appropriate conditions exist. Thus, finding a way to prevent these changes is really important for meat processing. (Bruce, 2014)
Sodium nitrite is a salt and an anti-oxidant. Salt (sodium chloride or table salt) containing some sodium nitrate and lesser amounts of sodium nitrite as impurities was used by the ancient Egyptians and Romans as well as the early Europeans to preserve meat. From these early experiences evolved products such as hams, bacon, sausages, bologna, salami and pepperoni. Sodium nitrite has been found to inhibit growth of disease-causing microorganisms; give taste and color to the meat; and inhibit lipid oxidation that leads to rancidity. (Sindelar et al, 2012)
Sodium nitrite is the inorganic compound with the chemical formula NaNO2. It is a white to slightly yellowish crystalline powder that is very soluble in water and is hygroscopic. The ability of sodium nitrite to address the above-mentioned issues has led to production of meat with improved food safety, extended storage life and improving desirable color or taste. Different sodium nitrite addition has effects on the texture of pork during curing. (Zumdahl, 2009) This experiment was going to use sodium nitrite to treat the raw fresh beef, in order to study the effect and function of sodium nitrite in meat curing.

Materials and Methods (Bruce, 2014)

Material The raw ground beef and sodium nitrite and was prepared by TA. This experiment need a long glass rob, plastic wrap, rubber band, two beakers and two plastic bags. The scales, weighing paper and medicine spoon also need to weight the sodium nitrite and meat. In the second day, the hot water bath was need for meat cooking.

Experiment Procedures:
1. 200g raw ground beef was weight and separated into 100g for each in the plastic bag.
2. 0.016g of…