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Yusuf IO, Adediran OA*, Awodoyin RO, Olusola OO, and Omojola AB
Department of Animal Science, University of Ibadan, Ibadan, Nigeria
Abstract
This study was designed to determine the physicochemical and organoleptic properties of
Greek yoghurt fortified with or without honey and Omega-3 fatty acids at different inclusion levels. Greek–type
yoghurt was prepared in seven formulations thus: No addition of honey and Omega-3 fatty acid (Treatment 1),
honey at 5% inclusion level (Treatment 2), honey at 7.5% inclusion level (Treatment 3), honey at 10% inclusion
level (Treatment 4), honey at 5% inclusion and Omega-3 fatty acid at 2% inclusion level (Treatment 5), honey
at 7.5% inclusion level and Omega-3 fatty acid at 2% inclusion level (Treatment 6) and honey at 10% inclusion level
and Omega-3 fatty acid at 2% inclusion level (Treatment 7). The organoleptic properties, physicochemical properties,
Thiobarbituric Acid Reactive Substances (TBARS) and microbial loads of yoghurts were determined using standard
procedures on days 0, 7 and 14 of storage in a completely randomized design. Data were subjected to
ANOVA at α-0.05. There were significant differences among the microbial population of the treatments (P<0.05).
Formulated yoghurt samples revealed T7 as having the highest microbial load (5.54± 0.21 CFU/mL) while T5 had the lowest (0.22± 0.03 CFU/mL). Treatment 4 was significantly higher (P<0.05)
in fat (0.94± 0.02%), WHC (74.14± 0.08 g/kg-1) and titratable acidity (0.89± 0.00 g/L) and had the lowest value in pH (4.08± 0.02),
total solids (33.50± 0.05%) and crude protein (7.06± 0.04%) w. In comparison, treatment 7 was significantly higher (P<0.05) in
syneresis (35.96± 0.13%) and lactose (3.08± 0.12). Fat, total solids, pH and WHC, declined with storage days while titratable acidity,
moisture content and syneresis increased with storage days. The yoghurts were generally well accepted and rated by the panellists
in this trend: T2>T3>T4>T6>T5>T7>T1.
Keywords: Greek-type yoghurt, Microbial load, Milk, Organoleptic properties, Physico-chemical, Thiobarbituric acid reactive substances
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