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STUDIES ON EFFECTS OF GAMMA IRRADIATION ON DEODORIZATION OF COCONUT OIL AND SHELF LIVES OF
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STUDIES ON EFFECTS OF GAMMA IRRADIATION ON DEODORIZATION OF COCONUT OIL AND SHELF LIVES OF TUBEROSE AND MARIGOLD CUT FLOWERS
Probir Kumar Ghosh, Sayani Pal and Paramita Bhattacharjee*Probir Kumar Ghosh, Sayani Pal and Paramita Bhattacharjee*Department of Food Technology and Biochemical Engineering, Jadavpur University, Department of Food Technology and Biochemical Engineering, Jadavpur University,
Kolkata 700 032, India(*Corresponding author: [email protected])(*Corresponding author: [email protected])
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Among oil crops, coconuts occupy a prime niché in south India and are also extensively cultivated in West Bengal. Coconut oil is a rich source of lauric acid, besidesmother’s milk and is a rich house of phytochemicals (such as phenols, alkaloids and glycosides); however, its usage as an edible oil in eastern India is limited owing to its
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mother’s milk and is a rich house of phytochemicals (such as phenols, alkaloids and glycosides); however, its usage as an edible oil in eastern India is limited owing to itsunpleasant lactonic odor. Among the horticultural produce, tuberose and marigold flowers are extensively cultivated in West Bengal. These flowers are highly valued fortheir ornamental appeal and reportedly have therapeutic potency. However, their short shelf lives limit their commercial utilization for export and therapeutic applications.their ornamental appeal and reportedly have therapeutic potency. However, their short shelf lives limit their commercial utilization for export and therapeutic applications.Therefore, there is huge wastage of these oil crops and horticultural products. In our study, low to medium dose irradiation has been employed for reduction of off-odor ofcoconut oil (for wider acceptability as frying oil) and for enhancement in shelf lives of tuberose and marigolds cut flowers (for preserving their therapeutic potential). Thecoconut oil (for wider acceptability as frying oil) and for enhancement in shelf lives of tuberose and marigolds cut flowers (for preserving their therapeutic potential). Theeffects of irradiation on these commodities were analyzed by hedonic sensory evaluation and assays of their physiochemical and phytochemical properties. Our studiesshowed promising results in reduction of obnoxious odor in coconut oil and extension of shelf lives of these flowers with concomitant preservation of their physiochemicalshowed promising results in reduction of obnoxious odor in coconut oil and extension of shelf lives of these flowers with concomitant preservation of their physiochemicaland phytochemical properties.
�� �� ���� � ���� ������������� �Irradiated marigold
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�
Overall appearance
Irradiated marigold flower (0.02-0.8 kGy) on day 5
Irradiated marigold flower (1.0-2.0 kGy) �
Overall
appear… Irradiated
coconut �
Overall appearanc
e
Irradiated tuberose flower (0.05 kGy) on
� Coconut oil, most commonly obtained from thedried coconut kernel (copra) is rich in
�Both tuberose and African marigold cut flowersare ornamental flowers; however, they haveshort shelf lives which limit their commercial
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Color
Visual fungal
flower (1.0-2.0 kGy) on day 5
Irradiated marigold flower (2.3 kGy) on
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ColorAfter taste
coconut oil (4 kGy) at 3 months
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Shrinkage
day 5
Irradiated tuberose flower
dried coconut kernel (copra) is rich inphytochemicals (such as phenols, alkaloids andglycosides) [1, 2] but has a characteristicobnoxious odor owing to presence of lactones and
short shelf lives which limit their commercialvalue
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� Colorfungal infestati
on
flower (2.3 kGy) on day 5
Irradiated marigold flower (2.5 kGy) on day 5
�
Homogen
ity
Mouthfeel
Irradiated coconut oil (6 kGy) at 3 months
�
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ColorShrinkage of petals
tuberose flower (0.05 kGy) on day 5
Non-irradiated
obnoxious odor owing to presence of lactones andoctanoic acid [3] which limit its use as an edible oil �Common procedures for preservation of
flowers include chemical preservatives and/orCAP/MAP packaging, which may leave harmful
FirmnesShrinkage of
day 5
Experimental control on day 5
OdorBody
Non-irradiated coconut oil oil at 3 months
AromaFirmness
Non-irradiated tuberose flowers on day 5� The conventional physical refining processes
cause thermal degradation of phytochemicals
CAP/MAP packaging, which may leave harmfulresidues in flowers and increase the cost,respectively [4] Firmnes
sge of petal
Negative control on day 5
Sensory evaluation of irradiated coconut oil, tuberose and marigold flowers with respect to
Taste
monthsrespectivelyrespectively [4]
Sensory evaluation of irradiated coconut oil, tuberose and marigold flowers with respect to control
Non-thermal green technology of gamma (�) irradiation
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2.3 kGy
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Non-thermal green technology of gamma (�) irradiation
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1.0 kGy��
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Control
LDPE
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� Reduction in obnoxious odor in coconut oil by �-irradiation�
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% M
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Storage (days)
1.0 kGy
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% M
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Storage (days)
LDPE
� Reduction in obnoxious odor in coconut oil by �-irradiation� Improvement in shelf life of tuberose and marigold cut flowers by �-irradiation� Study of shelf lives of irradiated coconut oil, tuberose and marigold flowers by Storage (days)
% Moisture of Irradiated Tuberose and Marigold Flowers with Storage� Study of shelf lives of irradiated coconut oil, tuberose and marigold flowers by
evaluation of sensory, physicochemical and phytochemical properties
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LDPEMaterials:� Oil and flowers:
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Tota
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(mg
Storage (days)
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Storage (days)
� Oil and flowers:� Coconut (Cocos nucifera L.) oil (expeller pressed from West coast tall variety coconut copra, M/s KPL Oil
Mills, Kerala, India).� Tuberose (Polianthes tuberosa L., Calcutta single variety) and marigold (Tagetes erecta L., African variety) cut
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Total phenol content of irradiated tuberose and marigold flowers with storage� Tuberose (Polianthes tuberosa L., Calcutta single variety) and marigold (Tagetes erecta L., African variety) cut
flowers were procured from Barasat, 24 Paraganas (N), West Bengal and authenticated by West Bengal FoodProcessing and Horticulture Development Corporation Limited, Kolkata.
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valu
e of
DP
PH
as
say
(mg/
mL) 0 kGy
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valu
e of
DP
PH
ass
ay
mL)
2.3 Kgy
2.5 Kgy
Processing and Horticulture Development Corporation Limited, Kolkata.� Packaging material:� PET bottles and LDPE packets (both authenticated by National Test House, Kolkata) were procured form a local
supermarket.
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IC50
valu
e of
DP
PH
as
say
(mg/
0.05 kGy
1.0 kGy
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50va
lue
of D
PP
H a
ssay
(m
g/m
L
Control
LDPE
supermarket.� Chemicals:� DPPH (M/s Sigma, USA), ethanol, sodium carbonate and Folin-Ciocalteu (M/s Merck, Germany).� Gamma Irradiation Facility: �
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Storage (days)
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IC50
Storage (days�
Value of DPPH Radical Scavenging Activity of Irradiated Tuberose and Marigold Flowers IC50 Value of DPPH Radical Scavenging Activity of Irradiated Tuberose and Marigold Flowers
� Gamma Irradiation Facility:� GC 5000 unit (BRIT, Mumbai) at National Instruments Laboratory (NIL) campus, Jadavpur University (JU).
Value of DPPH Radical Scavenging Activity of Irradiated Tuberose and Marigold Flowers IC50 Value of DPPH Radical Scavenging Activity of Irradiated Tuberose and Marigold Flowers with Storage
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�From 3 months study, greatest reduction in obnoxious odor (sensorically) of coconut oilNon-irradiated/ non packaged
Marigold cut flowers (negative control)Tuberose cut flowersCoconut oil
�From 3 months study, greatest reduction in obnoxious odor (sensorically) of coconut oilwas found in 4-6 kGy, without affecting physiochemical and phytochemical properties
�Irradiation at 0.05 kGy for tuberose flowers showed maximum shelf life (12 days) vis-a-�Irradiation at 0.05 kGy for tuberose flowers showed maximum shelf life (12 days) vis-a-vis control (non-irradiated flowers, 9 days) with appreciable antioxidant properties
�2.3 kGy was found to be the optimized dose of irradiation for marigold flowers, leading�2.3 kGy was found to be the optimized dose of irradiation for marigold flowers, leadingto enhancement of shelf-life by 6 days w.r.t. non-irradiated/non packaged flowers (shelf-life of 5 days)
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LDPE packaged/�-
irradiated at 0.02-
LDPE packaged/ non-irradiated(experimental Flowers packaged in LDPE
packets
life of 5 days)
irradiated at 0.02-2.5 kGy
(experimental control)packets
This study established novel applications of gamma irradiation technology forreduction of obnoxious odor of coconut oil and improvement of shelf life ofStorage atStorage at
23 � 2�C, 80% RH (in a humidity chamber)
Oil packaged in nitrogen flushed PET bottles
�-irradiation at 0.05 and 1.0 kGykGy
reduction of obnoxious odor of coconut oil and improvement of shelf life oftuberose and marigold cut flowers, without affecting their physiochemical andphytochemical properties
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(in a humidity chamber) (in a humidity chamber)
Selection of 2 favorable dose of �-irradiation at 2, 4, 6, 8 and 10
kGy
Flowers stored at 15�1�C, 70%
phytochemical properties
��������������������1. Dayrit C. (1997). Medicinal aspects of coconut oil, Coconuts Today, 14, 5-19.2. Ghosh P.K., Bhattacharjee P., Mitra S. and Poddar-Sarkar M. (2014). Physicochemical and Phytochemical
Analyses of Copra and Oil of Cocos nucifera L. (West Coast Tall Variety), International Journal of Food
Selection of 2 favorable dose of irradiation out of 13 doses (0.02-2.5
kGy) by sensory analyseskGy and storage at 23�2�C in
darkFlowers stored at 15�1�C, 70%
RH (in a controlled environmental chamber) Analyses of Copra and Oil of Cocos nucifera L. (West Coast Tall Variety), International Journal of Food
Science, Article ID: 310852, http://dx.doi.org/10.1155/2014/310852.3. Santos JER, Villarino BJ, Zosa AR and Dayrit FM. (2011). Analysis of volatile organic compounds in virgin
coconut oil and their sensory attributes, Phillipine Journal of Science, 140, 161-171.Physicochemical
(%moisture), phytochemical (total
chamber)
Evaluation of Evaluation of Evaluation of Evaluation of
sensory, physicochemical and coconut oil and their sensory attributes, Phillipine Journal of Science, 140, 161-171.4. Halevy AH and Mayak S. (1981). Senescence and post harvest biology of cut flowers II. Horticulture
Reviews, 3, 59-143.
(%moisture), phytochemical (total phenol content and DPPH activities)
analyses of selected irradiated flowers
Evaluation of sensory, physicochemical and
phytochemical properties of irradiated flowers
irradiated oil samples
sensory, physicochemical and phytochemical properties of
irradiated oil samples
���� � ���� �� ����� � ���� �� �w.r.t. controlw.r.t. control
Optimization of best irradiation
irradiated flowersirradiated flowers���� � ���� �� ����� � ���� �� �
Probir Kumar Ghosh acknowledges DST-INSPIRE (IF: 131031) and Sayani Pal acknowledges UGC-Optimization of best irradiation dose and assessment of shelf lifeAssessment of shelf lifeAssessment of shelf life
Probir Kumar Ghosh acknowledges DST-INSPIRE (IF: 131031) and Sayani Pal acknowledges UGC-NET; Ref. No.: 1575/(NET-JUNE 2012) for providing financial assistance for the study. The authors aregrateful to the Department of FTBE, JU for infrastructural facilities.