Assessment Of Ulam Raja (Cosmos Caudatus) Extract As A Functional Ingredient In Beef Patty And Green Tea
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Date
2015-02
Authors
SEYEDREIHANI, SAYEDEH FATEMEH
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Abstract
Natural and synthetic antioxidants have the ability to scavenge reactive
oxygen species, hinder oxidative degradation of lipids and thus enhance the
nutritional value of food. This thesis aimed to evaluate the potential use of Cosmos
caudatus as a functional ingredient in food and beverage. In the first phase of this
study, the total phenolic contents (TPC) and antioxidant activities of five popular
Malaysian raw salads or Ulam were investigated by using Folin-Ciocalteu, DPPH
radical scavenging (TEACDPPH) and reducing ferric ion antioxidant power
(TEACFRAP) assays respectively. Results confirmed that Ulam raja possesses the
highest antioxidant activities. In the next phase, the effect of heating time (30, 45 and
60 min) and temperature (45, 65 and 85◦C) on the extraction yield (Bx) of Ulam
raja was studied by using a face-centered composite design (FCCD). The optimum
extraction yield (4.2 Bx) was obtained by using 85◦C heating temperature for 30
min. To elucidate and quantify some marker compounds in the extract, high
performance liquid chromatography (HPLC) was used. The chromatographic data
illustrated the presence of several flavonoids i.e. quercitrin, catechin and rutin in
lyophilized Ulam raja extract powder (UREX). Their quantities were reported as
36.9mg, 25mg and 8.2 mg per g dried extract powder (UREX) respectively.
Acquiring an ORAC value equivalent to 2833 μmol TE, UREX was utilized as a
high-ORAC functional ingredient in beef patties. Incorporation of UREX or a
commercial green tea extract (GTE) at 500 mg/kg into beef patties reduced the
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extent of lipid and protein oxidation significantly (P<0.05). UREX showed strong
lipid and protein oxidation inhibitory effect, comparable with those of GTE. In
addition, significant improvement (P<0.05) in cooking yield and textural properties
was also recorded. In the last phase of the study, UREX was assessed for its potential
application as a nutraceutical in tea beverage. UREX was added into green tea at 25
and 50 mg per sachet, and the changes in color, antioxidant activities and sensory
characteristics of the samples (control without UREX, LUREX: 25mg/sachet, and
HUREX: 50 mg /sachet) were evaluated. Overall acceptability of samples added
with HUREX was significantly improved compared to LUREX and control.
Yellowness (b*) and chroma were also significantly (P<0.05) increased. TEACDPPH
and TPC were significantly (P<0.05) higher in sample treated with HUREX
compared to the other two (LUREX and control). In conclusion, this thesis pointed
to the potential value of using UREX as a functional ingredient in food (beef patty)
and beverage (green tea).
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Assessment Of Ulam Raja (Cosmos Caudatus) Extract As A Functional Ingredient , In Beef Patty And Green Tea