Proximate analysis
Moisture and ash content and pH of each meatball
were measured using AOAC (1990) procedures. Fat
content was determined by chloroform–methanol extraction
according to, Flynn and Bramblett (1975).
Protein content was determined according to Anon
(1979). For each treatment analyses were done on five
meatballs.
2.3. Cooking procedure and cooking measurements
Meatballs were thawed at 4 C overnight and were
cooked in a preheated electric grill for 4 min each side.
All cooking measurements were done on 5 replicates per
treatment. Percent cooking yield was determined by
calculating weight differences for samples before and
after cooking. Cooking yield and fat retention were
calculated according to Murphy, Criner, and Grey
(1975).
Cooking yield ð%Þ
¼ ðCooked meatball weightÞ
=ðUncooked meatball weightÞ 100:
Fat retention ð%Þ
¼ ½ðCooked weightÞ ð% Fat in cooked meatballÞ
=ðRaw weightÞ ð% Fat in raw meatballÞ 100:
Moisture retention ð%Þ
¼ ð% Yield % Moisture in cooked meatballÞ=100:
The reduction in meatball diameter was determined with
a ruler using the following equation:
Reduction in meatball diameter ð%Þ
¼ ðUncooked meatball diameter
Cooked meatball diameterÞ
=ðUncooked meatball diameterÞ 100:
The reduction in meatball thickness was determined
using the following equation:
Reduction in meatball thickness ð%Þ
¼ ðUncooked meatball thickness
Cooked meatball thicknessÞ
=ðUncooked meatball thicknessÞ 100:
Moisture retention value represents the amount of
moisture retained in the cooked product per 100 g of
sample and was determined according to an equation by
El-Magoli, Laroia, and Hansen (1996).
Meatball dimensional shrinkage was calculated
according to following equation:
Shrinkage ð%Þ
¼ ½ðRaw thickness Cooked thicknessÞ
þ ðRaw diameter Cooked diameterÞ
=ðRaw thickness þ Raw diameterÞ 100:
2.4. Sensory evaluation
Meatballs were served warm to a six-membered
trained panel (graduate students and staff of Ege University,
Food Engineering Department) who assessed
appearance, texture, juiciness, flavour and overall acceptability.
An eight point scale was used where,
8¼extremely desirable, extremely tender, juicy, intense
in beef flavour and 1¼denoted extremely undesirable,
extremely tough, dry, devoid of beef flavour. Water and
bread served for cleaning the mouth between samples.
2.5. Statistical analysis
The trial was performed twice. Data were subjected
to analysis of variance and Duncans Multiple Test (Steel
& Torrie, 1980) was used to determine the significant
differences among means. Significance of differences was
defined as (p < 0: