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Intl. J. Food. Ferment. Technol. 7(2): 279-285, December 2017
©2017 New Delhi Publishers. All rights reserved
DOI: 10.5958/2321-5771.2017.00038.2
Rosa damascena: Quality Evaluation and Process
Optimization for the Development of Rose Syrup
Ashwani Kumar1,3*, Amarjeet Kaur1, V.K. Joshi2 and Vikas Kumar3
Dept. of Food Science and Technology, Punjab Agricultural University, Ludhiana, India
Dept. of Food Science and Technology, Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni, Solan, India
Dept. of Food Science and Nutrition, Lovely Professional University, Phagwara, India
*Corresponding author: ashwanichandel480@gmail.com
Paper No.: 190 Received: 25-07-2017 Revised: 08-11-2017 Accepted: 09-12-2017
Abstract
Rosa damascena also known as desi gulaab, belongs to the Damask variety of rose. It is deep red coloured variety with a
sweet fragrance and has been used traditionally in dierent food preparations. Physico-chemical evaluation revealed that
it is a rich source of phytochemicals. The content of phenolic compounds, anthocyanins, ascorbic acid and per cent radical
scavenging activity in the fresh petals was 2230 mg GAE/100 g, 98.64 mg/100g, 293.37 mg/100 g and 83.91%, respectively.
Fresh petals were also a good source of minerals. The content of potassium, phosphorus, calcium, copper and iron was
153.39 mg/100g, 34.59 mg/100g, 13.78 mg/100g, 1.82 mg/100g and 1.33 mg/100g, respectively. It was concluded from the
optimization process that 30:70 of rose petals to sugars, produced syrup with high overall acceptability and in compliance
with the specications of Food Safety and Standardization Authority of India. Whereas, the optimization of temperature
revealed that heat treatment at 70°C was most suitable to produce a syrup rich in phytochemicals and high sensorial
acceptability.
Keywords: Desi rose, phytochemicals, FSSAI, rose syrup.
Edible owers have been used traditionally to
improve the aesthetic appearance, taste and value
of foodstus. Among various civilizations such as
Asian, East Indian, European, Victorian English,
and Middle Eastern the owers have been used
for food and medicinal purpose since ancient time
(Kaisoon et al. 2012). Edible owers are emerging as
new source of nutraceuticals due to their nutritional
and medicinal value (Mlcek and Rop, 2011). In
European countries, the owers are generally used
for preparation of hot beverages (tisane or infusion)
like tea and a great advantage is that they are free
from caeine (Navarro-González et al. 2015). Rosa
spp. is diverse and at present over 200 species and
more than 18000 cultivars form of the plant has been
identied (Boskabady et al. 2011). Many species of
rose (Rosa spp.) were used in ancient Greece and
Rome as relishes and avour enhancers of many sweet
and savoury dishes while in the Indian Ayurveda
system, various rose preparations were used as tonic,
laxative, astringent and antibacterial agent (Verma et
al. 2011). In ancient India rose petals were preserved
in the form of Gulkand (rose petals preserve) or
fragrant syrup known as Gulkand Sharbat (Kumar,
2017). The health benets of rose are well known and
several pharmacological properties including anti-
HIV, antibacterial, antioxidant, antitussive, hypnotic,
antidiabetic, and relaxant eect on tracheal chains
have been reported for this plant (Boskabady et al.
2011). Rose and rose products are also used as a
cooling agent and as a vehicle for many Ayurvedic
medicines (Kaul, 1998). A range of traditional
RESEARCH PAPER
280
Kumar et al.
products have been produced using desi gulab (Rosa
damascena) in North India but a documented record
for its physicochemical composition as well as a
standard process which meets the Food Safety and
Standard Authority of India (FSSAI) specications
is lacking. Therefore, in the present study proximate
composition of the ower was determined and a
process was optimized to produce articial additives
free rose syrup according to the FSSAI specications.
MATERIALS AND METHODS
COLLECTION OF RAW MATERIAL
Fresh petals of desi gulab were collected from the
department of Floriculture and Landscaping, Punjab
Agricultural University, Ludhiana. The petals were
collected on a clear sunny day aer the evaporation
of dew. Crystalline table sugar used in the study was
purchased from the local market, PAU, Ludhiana.
The fresh petals were analysed for dierent physico-
chemical characteristics (Table 1).
Standardization of process for production of rose
syrup
The optimization was carried in two steps. In the rst
step the ratio of rose petals to sugar was optimised
to produce syrup with TSS in accordance to FSSAI
standards i.e. 65 °B. Six treatments comprising rose
petals to sugar ratios from 24:76 to 34:66 (Table 3)
were selected and the rose syrup was prepared using
the osmotic process. Cleaned petals and sugar were
lled in glass jars as per the selected treatments
and were covered. The lled jars were le at room
temperature for 2 days for the slow dissolution of
sugar. The jars were stirred occasionally in between.
Aer two days all the jars were subjected to heating
at 100°C for the complete dissolution of sugar and
to increase the extraction of colour and avour. In
the second optimization the eect of temperature
was studied on the quality of rose syrup. The best
combination selected for rose petals to sugar was
subjected to dierent temperatures i.e. 70, 80, 90
and 100°C for 1 hour. The schematic diagram of the
syrup preparation process is shown in Fig. 1. The
prepared syrups were analysed for various physico-
chemical and sensory aributes and on the basis of
these parameters best temperature was selected for
the production of rose syrup.
Fresh rose petals
↓
Washing in clean tap water
↓
Addition of sugar and petals in subsequent layers in
the glass jar
↓
Application of lid
↓
Maceration at room temperature for 2 days
↓
Shaking the contents occasionally
↓
Keeping the jars in a hot air oven at 70º C for 1 hour
↓
Filtration through muslin cloth
↓
Filling into clean glass boles
↓
Corking and pasteurizing of boles
↓
Cooled and stored for further use
Fig. 1: Schematic diagram for the production of rose
syrup
Physico-chemical analysis
The prepared syrups were analysed for dierent
physico-chemical characteristics, viz. TSS, totals
solids, pH, ash as per the standard methods (AOAC,
1980). Crude protein was measured using Micro
Kjeldhal method (AACC, 2000). Total anthocyanins
and ascorbic acid were measured as per the method
described by Ranganna (1986). Total phenols were
estimated using the spectrophotometer at 760nm
(Singleton and Rossi, 1965). Antioxidant activity
Rosa damascena: Quality Evaluation and Process Optimization for the Development of Rose Syrup
281
(free radical scavenging activity) was measured as
per the method of Brand-Williams et al. (1995) using
DPPH (2, 2-diphenyl-1-picrylhydrazyl) dye. Colour
was determined using Hunter color lab and the
value of the colour was presented as ‘L’ (lightness),
‘a’ (redness) and ‘b’ (yellowness). The value of L
varies from 0-100; higher the value of L whiter the
product. Lower value of L indicates dark colour. The
positive value of ‘a’ indicates redness while negative
value indicates green colour. The positive value of
the b indicates yellowness while the negative value
indicates blueness.
Minerals
Mineral content of rose petals was determined by
thermos-electron inductively coupled plasma atomic
emission spectrometry (ICP-AES), model iCAP-630
(Arora and Bajwa, 1994). For this determination 10
ml of diacid was added to one gram of powdered
sample and was le overnight. Then the mixture was
digested until white fumes were observed, as per the
routine practice.
Sensory analysis
Coded samples of the developed rose syrup were
served to sensory panel for evaluation aer diluting
4 times with potable water. The panelists were asked
to rank the intensity of each aribute of the product
on a 9 point hedonic scale. Where, 1 means ‘dislike
extremely’ and 9 means ‘like extremely’. The judges
rinsed their mouth with water in-between the testing
of products. All the details were used as prescribed
for sensory evaluation of Food (Joshi, 2006).
Statistical analysis
The data was analysed with SPSS 16.0 soware
and the results are represented as mean ± Standard
deviation (SD) of three replicate assays. Signicant
dierences were determined by one way analysis
of variance (ANOVA) compared by Duncan’s test
(P≤0.05).
RESULTS AND DISCUSSION
Physico-chemical analysis of fresh rose petals
Table 1 depicts the composition of the petals of desi
gulab locally grown in Punjab. Fresh petals had high
moisture content i.e. 86±2.15% and the juice extracted
from the petals had a total soluble solids content of
8.37±0.15 °B. Singh (2014) reported a moisture content
of 84±1% in fresh marigold owers.
Table 1: Physico-chemical properties of fresh rose petals
Parameter Value
TSS (°B) 8.37± 0.15
Moisture (%) 86± 2.15
Crude Protein (%) 1.70± 0.28
Crude fat (%) 0.46± 0.06
Crude bre (%) 2.57± 0.42
Total Phenols (mg GAE/100g) 2230± 26.40
Anthocyanins (mg/100g) 98.64±0.36
Antioxidants (% radical scavenging activity) 83.91±2.53
Ascorbic Acid (mg/100g) 293.37±7.49
pH 5.47±0.06
Ash (%) 0.36±0.02
Colour
L*- lightness 53.54
a*- + red; - green 17.25
b* - + yellow; - blue -0.6
The crude protein content of fresh rose petals was
1.70±0.28%. The results are in conformation with Rop
et al. (2012) who reported 2.66% of proteins in rose.
Data (Table 1) revealed that fresh rose petals were
rich source of phyto-chemicals such as total phenols,
anthocyanins, ascorbic acid and antioxidants. Fresh
petals had a total phenolic content of 2230±6.40 mg
gallic acid equivalent (GAE) per 100 g of fresh petals.
The total phenolic content was well in accordance
with Ge and Ma, (2013) who reported a total phenolic
content of 2087.43±17.37 mg GAE/100g in fresh
edible rose petals of Yunnan, China. The anthocyanin
content of desi gulab petals was 98.64±0.36 mg/100g
which was however; lower than 353.56± 2.50 mg/100g
reported for the edible roses of Yunnan region, China
282
Kumar et al.
(Ge and Ma, 2013). The dierence in anthocyanin
content might have been due to the variation in
the variety and region. The fat content of fresh rose
petals was 0.46± 0.06%. The damask rose petals have
been reported to have very low content of essential
oil and 3000 Kg of rose petals are required to obtain
1 Kg of essential oil (Verma et al. 2011). The ascorbic
acid content of desi gulab was higher (293.37±7.49
mg/100g) compared to 54.5 mg/100g reported by
Karami et al. (2016) for fresh petals of Persian musk
rose (Rosa moschata Hermm)). The dierence might
have been due to the white colour of Persian musk
rose. Ash and crude bre content of petals were
0.36% and 2.57%, respectively.
Colour estimation of rose petals revealed ‘L’
(lightness) value of 53.54, ‘a’ value of 17.25 and ‘b’
value of -0.6. ‘L’ value of 53.54 revealed that the rose
variety used in study was rich in pigments. Positive
‘a’ value indicates the redness of colour while the
negative ‘b’ value is an indication of blue colour. The
intensity of blue and red colour might have been due
to the presence of the anthocyanins. The anthocyanins
range from red to blue colour (Mazza and Miniati,
1993) and are responsible for the colour of many fruit
and vegetables.
Table 2: Mineral content of rose petals per 100g fresh weight
basis
Mineral Content (mg/100g)
Potassium 153.39
Phosphorus 34.53
Calcium 13.78
Sulphur 16.72
Magnesium 12.75
Sodium 7.61
Copper 1.82
Iron 1.33
Zinc 0.29
Table 2 represents the mineral content per 100 g
of fresh rose petals. The data revealed that fresh
petals had 153.39 mg of potassium, 34.53 mg of
phosphorus, 13.78 mg of calcium, 1.82 mg of copper,
1.33 mg of iron and 0.29 mg of zinc per 100 g. These
results were in accordance with Rop et al. (2012),
who reported the content of potassium, phosphorus,
calcium, magnesium, iron, copper and zinc as 196.9
mg/100g, 22.5 mg/100g, 27.5 mg/100g, 0.35 mg/100g,
0.23 mg/100g and 0.45 mg/100g, respectively for the
variety Rosa odorata. The mineral content reects that
a good contribution to the product like syrup can be
made if rose petals are used in preparation of such
products. Further, the rose petals have appreciable
amounts of both macro and micro elements, as
revealed by the results (Table 2).
Optimization of rose petals and sugar
Table 3 represents the eect of dierent ratios of
rose petals to sugar on the quality of rose syrup. It
is evident from Table 3 that with increase in quantity
of rose petals there was a signicant increase in total
phenols, anthocyanins, antioxidants and ascorbic
content. The increase in these parameters might
have been due to richness of rose petals in these
phytochemicals (Yassa et al. 2009; Nowak et al. 2014)
and same has been also observed in the analysis of
fresh rose petals (Table 1).
A signicant decrease in total soluble solids was
found with decrease in the sugar level and it
is understandable as the increase in petal ratio
decreased the syrup content, hence TSS of the syrup.
The most desirable TSS content (as per the FSSAI
specications) was achieved in treatments T4 and T5.
The rose syrup proved to be an appreciable source of
total phenols and ascorbic acid and accordingly had
appreciable antioxidants. There was an increase in
the colour and aroma of rose syrup with increase in
petal content.
However, the petals content above 30 per cent
resulted in a bier aer taste. The bier taste might
have been due to the bier compounds i.e. tanning
maer, fay oil and organic acids in the rose (Joshi,
2004; Nayeem et al. 2006; Boskabady et al. 2010). Based
on the FSSAI specications, sensory parameters and
phytochemical contents of the treatment T4 was
selected for further research.
Rosa damascena: Quality Evaluation and Process Optimization for the Development of Rose Syrup
283
Fig. 2: Sensory profile of different rose syrups prepared in
laboratory
Where, T1- 24:76 of rose petals to sugar, T2- 26:74 of rose
petals to sugar; T3-28:72 of rose petals to sugar, T4-30:70 of
rose petals to sugar; T5- 32:68 of rose petals to sugar, T6:
34:66 of rose petals to sugar
Temperature optimization
To overcome the problems of rst standardization
i.e. bier aertaste and cooked avour the next
optimization was done for the selection of most
suitable temperature to prepare a product with
refreshing taste of rose, lowest possible bier aertaste
and maximum phytochemicals. Table 4 depicts
the eect of various temperatures on the physico-
chemical parameters of rose syrup. Temperature
had slight but signicant (P≤0.05) eect on the total
soluble solids, total solids and pH contents of the
rose syrup and an increase in these parameters was
recorded with increase in temperature. This increase
might have been due to the evaporation of water and
more leaching of the soluble compounds from petals
at a higher temperature. A signicant decrease was
found in total phenols and anthocyanins content on
decreasing the temperature which might have been
due to the incomplete leaching of soluble components
at low temperature. Heating is known to soen the
plant tissue and weaken the phenol-protein and
phenol-polysaccharide interactions (Mokrani et al.
2016) and hence more migration of phenols and
anthocyanins to the solvent from the petals takes
place at a high temperature. Ascorbic acid content
was decreased with increase in process temperature
which might have been due to the oxidation of
antioxidants at higher temperature and same has
been observed for pomegranate juice by Paul and
Ghosh, (2012). The least lightness value (36.27) for
syrup was obtained at 70°C while the redness value
was maximum at 70°C and minimum at 100°C which
might have been due to the leaching of chlorophyll at
high temperature.
Sensory analysis
Fig. 3 depicts the eect of temperature on the sensory
Table 3: Effect of different ratios of petal sugar ratio on quality attributes of rose syrup
Treatments T1(24:76) T2(26:74) T3(28:72) T4(30:70) T5(32:68) T6(34:66)
Parameters
TSS (°B) 72.63±1.07 a 70.43±0.91 b 68.63±0.25 c 67.50±0.75 c 64.4±0.81 d 62.47±1.00 e
Total Phenols (mg GAE/100g) 498±12.12a525±9.74ab 580±5.72bc 625±6.20cd 658±7.07de 716±5.80e
Anthocyanins
(mg/100g) 21.87±0.37 a 24.01±0.60 b 25.79±0.40 c 28.05±0.65 d 30.28±0.66 e 31.84±0.72 f
Antioxidants
(% radical scavenging activity) 10.20±0.27a13.30±0.30b15.51±0.40c16.75±0.38d18.43±0.26e19.34±0.19f
Ascorbic Acid
(mg/100g) 14.60±2.03 a 16.43±2.97 b 19.93±0.5bc 21.57±0.78c23.73±0.35d26.83±0.40d
*Values are means ± SD of 3 replications. Dierent superscripts in a column indicate that they are signicantly (p≤0.05)
dierent to each other determined by Duncan’s tests.
284
Kumar et al.
aributes of the rose drink on a 9 point hedonic scale.
Highest overall acceptability was obtained for the
syrup prepared at 70°C. The score for other sensorial
parameters like colour, avour and mouthfeel was
also found highest at this temperature.
Fig. 3: The effect of temperature on the sensory scores of
rose syrup on a 9 point hedonic scale
Flavour and mouthfeel had more eect of temperature
as compared to overall acceptability. Based on the
physico-chemical (Table 4) and sensory evaluation
(Fig. 3) of prepared syrups, it was concluded that a
temperature of 70 °C was most suitable to prepare
a product rich in phytochemicals and high sensory
acceptability.
CONCLUSION
Desi gulab (Rosa damascena) variety of rose is rich in
phyto-chemicals such as anthocyanins, phenols,
antioxidants and ascorbic acid. It is also a rich
source of vital minerals like calcium, phosphorus,
potassium, zinc and iron. Further, its deep red
colour and pleasant avour made it suitable for the
preparation of natural rose syrup free from chemical
colourants and avourings. A low temperature
processing retains maximum phyto-chemicals and
gives a relishing pleasant taste. Such syrups can be
used as a health tonic and an alternative to existing
products which make use of chemical additives.
ACKNOWLEDGEMENTS
The authors are thankful to Department of Science
and Technology, New Delhi for providing nancial
Table 4: Effect of temperature on physicochemical quality characteristics of rose syrup
Temperature 100°C 90°C 80°C 70°C
Parameters
Total soluble Solids (°B) 67.00±1.08 a 66.63±0.38 a 66.10±0.40 ab 65.20±0.26 b
Total Solids (%) 68.51±0.24a68.00±0.20a67.17±0.42b66.13±0.40c
pH 6.81±0.03b6.80±0.01b6.81±0.03b6.86±0.02a
Total phenols
(mg GAE/100g) 625±6.20 a 576±3.22 b 538±3.80 c 520±4.67 d
Antioxidants
(% radical scavenging activity) 16.75±0.38d20.19±0.94c22.80±0.60b24.53±0.76a
Ascorbic Acid (mg/100g) 21.57±0.78d25.57±1.76c30.11±1.03b34.87±2.73a
Anthocyanins
(mg/100g) 28.05±0.65a26.07±0.38b22.96±0.88c21.16±0.30d
L 37.31±0.02 a 37.21±0.03 a 36.93±0.153 a 36.27±0.15 a
a -.057±0.012d0.007±0.002c0.53±0.058b0.67±0.058a
b -2.34±0.006 a -2.32±0.010 a -2.31±0.006 a -2.31±0.006 a
*Values are means ± SD of 3 replications. Dierent superscripts in a column indicate that they are signicantly (P≤0.05)
dierent to each other determined by Duncan’s tests.
Rosa damascena: Quality Evaluation and Process Optimization for the Development of Rose Syrup
285
support through DST INSPIRE Fellowship vide IF
140519 during Ph.D. programme.
REFERENCES
AACC. 2000. Approved Methods of the AACC, 10th edition.
American Association of Cereal Chemists, St. Paul, USA.
AOAC. 1980. Association of Ocial Analytical Chemists.
Ocial Methods of Analysis. Hortiritz, W. (ed.) 13th edn.
Washington D.C, USA.
Arora, C.L. and Bajwa, M.S. 1994. Comparative study of some
methods of oxidation of plant materials for elemental
analysis. Current Science, 66: 314-316.
Boskabady, M.H., Shafei, M.N., Saberi, Z. and Amini, S. 2011.
Pharmacological eects of Rosa damascena. Iranian Journal
of Basic Medical Sciences, 14(4): 295-307.
Brand-Williams, W., Cuvelier, M.E. and Berset, C. 1995. Use
of a free radical method to evaluate antioxidant activity.
Lebensm.-Wiss. Technol., 28: 25–30.
FSSAI. 2010. Final regulations. Retrieved from hp:// www.
fssai.gov.in/0/Final Regulations_2010.pdf
Ge, Q. and Ma, X. 2013. Composition and antioxidant activity
of anthocyanins isolated from Yunnan edible rose (An
ning). Food Science and Human Wellness, 2: 68-74.
Joshi, S.G. 2004. Medicinal Plants. Oxford & IBH Publishing
Co. Pvt. Ltd. New Delhi.
Joshi, V.K. 2006, Sensory Science-Principles and application in
Food Evaluation Agro tech Academy, Udaipur, (India).
Kaisoon, O., Konczak, I. and Siriramornupun, S. 2012.
Potential health enhancing properties of edible owers
from Thailand. Food Research International, 46: 563-571.
Karami, A., Jandoust, S., Eshghi, S. and Raof-fard, F. 2016. The
fresh petal of Persian rose (Rosa moschata hermm) as source
of nutraceutical foods. Vitamins and Minerals, 5(2).
Kaul, V.K. 1998. Damask rose-cultivation and processing
in supplement to cultivation and utilization of aromatic
plants (Eds., S.S. Handa and M.K. Kaul), Regional Research
Laboratory, Jammu, pp. 195-212.
Kumar, A., Kaur, A., Gill, K. and Aggarwal, P. 2017.
Development and economics of articial additives free
rose syrup from desi rose. Indian Journal of Economics and
Development, 13(2a): 536-539.
Mazza, G. and Miniati, E. 1993. Anthocyanins in Fruits,
vegetables, and grains. CRC Press, London.
Mlcek, J. and Rop, O. 2011. Fresh edible owers of ornamental
plants- A new source of nutraceutical foods. Trends in Food
Science and Technology, 22: 561-569.
Mokrani, A. and Madani, K. 2016. Eect of solvent, time and
temperature on the extraction of phenolic compounds
and antioxidant capacity of peach (Prunus persica L.) fruit.
Separation and Purication Technology, 162: 68-76.
Navarro-González, I., González-Barrio, R., García-Valverde, V.,
Bautista-Ortín, A. and Jesús Periago, M. 2015. Nutritional
composition and antioxidant capacity in edible owers:
characterisation of phenolic compounds by HPLC-DAD-
ESI/MS. International Journal of Molecular Science, 16: 805-
822.
Nowak, R., Otech, M., Pecio, L., Oleszek, R.L., Malm, A.
Rzymowska, J. 2014. Cytotoxic, antioxidant, antimicrobial
properties and chemical composition of rose petals. Journal
of Science and Food Agriculture, 94: 560-567.
Nyeem, M.A.B., Alam, M.A., Awal, M.A., Mostofa, M., Uddin,
M., Islam, S.J.N, et al. CNS Depressant Eect of the Crude
Ethanolic Extract of the Flowering Tops of Rosa Damascena.
Iranian Journal of Pharmaceutical Research; 5:171-174.
Ranganna, S. 1986. Handbook of analysis and quality control
for fruit and vegetable production, 2 edition, Tata McGraw-
Hill Publishing Co., New Delhi.
Rop, O., Mlcek, J., Jurikova, T., Neugebauerova, J. and Vabkova,
J. 2012. Edible owers-A new promising source of mineral
elements in human nutrition. Molecules, 17: 6672-6683.
Singh, I. 2014. Drying behaviour of French marigold Tagetes
patuala Linn owers. International Journal of Farm Sciences,
4(2): 100-106.
Singleton, V.L. and Rosi, J.A. 1965. Colorimeter of total
phenolics with phosphomolybdic phosphotungstic acid
reagents. American Journal Enology and Viticulture, 10: 144-
158.
Verma, R.S., Padalla, R.C. and Chauhan, A. 2011. Chemical
investigation of the volatile components of shade-dried
petals of damask rose (Rosa damascena Mill.). Archive
Biological Science, 63(4): 1111-1115.
Yassa, N., Masoomi, F., Rohani Rankouhi, S.E. and
Hadjakhoondi, A. 2009. Chemical composition and
antioxidant activity of the extract and essential oil of Rosa
damascena from Iran, Population of Gulian. Daru, 17(3): 175-
180.
Youssef, H.M.K.E. and Mousa, R.M.A. 2012. Nutritional
assessment of low-calorie baladi rose petals jam. Food and
Public Health, 2(6): 197-201.