**1. Introduction**

436 Olive Oil – Constituents, Quality, Health Properties and Bioconversions

Yusof S. C. & Babji, A. S. (1996), Effect of non-meat proteins, soy protein isolate and sodium

Vol.47, No.4, (July 1996), pp. 323-329.

caseinate, on the textural properties of chicken bologna. *Inter J. Food Sci Nutr.*,

The consumption of convenience foods in the restaurants such as beef or chicken burgers is increasing in Jordan. Burger is a meat product prepared from minced lean meat, with or without addition of other ingredients. The total fat content must not exceed 15% (JS: 1334/2002). In Jordan, burgers are prepared from two main meat sources: beef or chicken. Many efforts have been made to improve the quality and stability of burgers because consumer demand for healthy fast food has rapidly increased in the recent years.

Complete or partial replacement of burger fat with oil rich in monounsaturated fatty acids, such as olive oil may improve the oxidative stability of chicken burger and the nutritional value of beef burger. Another approach that can be followed to improve the quality of beef burgers is the partial replacement of beef meat with chicken meat.

This study aimed at:


Five burger formulations were prepared and studied during storage and after grilling at 75°C for 20 minutes. These formulations were: beef, chicken, mixed beef and chicken (50:50), beef with olive oil and chicken with olive oil.

The effect of storage and grilling was evaluated by determining cooking loss by using weight differences between raw and cooked burgers, thiobarbituric acid reactive substances (TBARS) (Faustman, *et al.*, 1992), fatty acid profile using GLC analysis; fatty acid methyl esters (FAMEs) of the burger samples were prepared according to Chritopherson and Giass (1969) method, cholesterol and 7-ketocholesterol; cold saponification and extraction was

<sup>\*</sup> Corresponding Author

Meat Fat Replacement with Olive Oil 439

Melton (1985) reported that oxidized flavors were detectable at TBARS numbers of 0.3-1.0 in beef or pork, 1or 2 in chicken, and higher than 3 in turkey. The TBARS values obtained in this study, remarkably exceeded these ranges. So it can be assumed that these high values of

On the other hand, decrease in TBARS values noticed at the end of storage period were 85, 60, 47, 18 and 3% for chicken with olive oil, chicken, beef with olive oil, mixed and beef treatments, respectively. This behavior may be ascribed to the combination of aldehydes

Different trends were observed on the effect of grilling on TBARS values, since TBARS values decreased in both beef samples, whereas they increased in both chicken samples. This finding may be attributed to the fact that chicken fat contains higher levels of PUFA,

It was evident that cholesterol content of the raw and grilled chicken sample was about 39% higher than those of beef sample. This is due to the use of chicken skin which contains high level of cholesterol in chicken burger. Mixed meat samples had cholesterol content which

Substitution of the added beef and chicken fat with olive oil resulted in a considerable decrease in cholesterol contents. The reduction in beef and chicken samples was about 53%

> a462.10 a461.67 a460.27 a461.35a

> a460.13 a459.37 a459.11 a459.54a

\* Values within the same column with same subscripts are not significantly (p> 0.05) different according

\*\* Values within the same row with different superscripts denote significant differences (p< 0.05) between treatments according to LSD, whereas values within the same column with same subscripts denote no significant (p> 0.05) differences among raw and grilled samples according to LSD.

Table 2. Cholesterol content (mg/100 g fat) for the raw and grilled burger samples during

\*Treatment

a391.67 a390.66 a390.47 b390.93a

a390.27 a389.30 a389.13 b389.57a

olive oil

a157.70 a156.61 a155.73 e156.68a

a156.47 a154.92 a154.67 e155.35a

Chicken with olive oil

> a193.43 a193.03 a192.00 d192.82a

> a191.13 a191.07 a190.28 d190.83a

Beef Chicken Mixed Beef with

with other compounds and to the loss of volatile aldehydes (Severini, *et al*., 2003).

TBARS could be attributed to oxidation as well as other interferences.

was about 15% lower than chicken and 18% higher than those of beef.

a333.87 a331.27 a331.30 c332.15a

a331.73 a330.23 a330.93 c330.96a

which are prone to higher level of oxidation.

**4. Cholesterol and cholesterol oxides** 

Time of storage (month)

Each value is the mean of three replicates.

and 58%, respectively

Characteristic

Raw

Grilled

to LSD.

storage.

carried out according to the method used by Sander, *et al.* (1988) and the trimethylsilyl derivatives (TMS) of cholesterol and cholesterol oxides were carried out according to the method used by Pie, *et al.* (1990).
