This internship report summarizes Harinandan Dev's project on concentrating and spray drying extracts of Hibiscus rosa-sinensis flowers under the guidance of Dr. Sukumar Debnath. The objectives were to extract anthocyanins from the flowers using forward osmosis concentration and analyze the extracts' quality. Anthocyanins were extracted from dried petals using citrate phosphate buffer. Forward osmosis concentrated the extract, reducing weight and moisture while increasing shelf life. Spray drying further converted the concentrated extract into a powdered form for easy storage, transport, and use in food products. Proximate analysis and anthocyanin content determination were conducted on fresh, dried, extracted, and concentrated samples.

1. INTERNSHIP REPORT
PRESENTATION
ON
“Concentration and Spray drying of
Hibiscus rosa sinensis extract
And its quality analysis”
Under the guidance of
Dr. Sukumar Debnath
Sr. Principle Scientist
Food Engineering Department
Prepared by: Harinandan Dev
Enroll. No. 2019BVOCFP07

2. 1. INTRODUCTION: Hibiscus rosa sinensis flower

3. 2. OBJECTIVES
2.1. Extraction of anthocyanin from Hibiscus rosa sinesis and concentration
using forward osmosis
2.2 Proximate analysis and bioactive compound analysis of Hibiscus rosa-
sinesis flower and its extracts.
2.3 Shelf-life extension of Hibiscus rosa sinesis flower concentrated through
spray drying

4. 3. MATERIALS AND METHODS
3.1 Sample
Fig. a. H. Rosa sinensis b. Petals. c. Shade dried
• Hibiscus rosa-sinensis: Fresh flowers with no apparent physical, insect or microbial
damage.
• Collected from: Karanji Lake & CFTRI CAMPUS, Mysore
• Flower Petals: Separated carefully
• Shade Drying: 2-3 days at room temperature

5. 3.2 Preparation of extract.
Table 1. Citrate phosphate buffer: Extracting solution
. Dried Petals
Nn. N n n n n n n n n n n Soaked ( 1:20 g/v)
(Citrate phosphate buffer)
(4 hrs)
Filter (Sieve)
Extract
(Stored in freeze)
Salts Concentration
Sodium Phosphate Dibasic
Dihydrate
0.102 M
Citric Acid 0.05 M

6. 3.3. Concentration of the extract.
Fig. Forward osmosis concentration.

7. 3.4 Spray drying of concentrated Hibiscus rosa-sinensis extract.

8. 3.5 Proximate Analysis
The system consists of determinations of water, ash, crude fat
(ether extract), crude protein and crude fibre.
• To the quantitative analysis of macromolecules in food
3.5.1 Hot Air Oven ( Moisture content)
Principle : Conduction; dry heat
Range : 50-250 Degrees celcius.
Applications: Articles sterilization,
105 Degree Celsius for Moisture est.

9. 3.5.2 Muffle Furnace (Ash Content)
Principle: Law of conservation of energy
Construction: Insulated firebrick walls to
maintain high temperatures, rugged
construction, programmable controllers,
and a safety switch that turns off power
when the door opens.
.i.e, For Ash content 550 degree Celsius

10. 3.5.3 Soxhlet apparatus/method (fat extraction)
Soxhlet method. Extracting lipids in foods;
Sample placed in a porous thimble.
three compartments; flask,
extraction chamber, and condenser.
Solvents used: Petroleum Benzene
(40-60 oC) B.P

11. 3.6 Spectrophotometer ( estimation of anthocyanins)

12. 4. RESULTS AND DISCUSSION
4.1 Extraction of anthocyanins from Hibiscus rosa sinesis
25g dried petals 500ml (buffer sol.) Filter
4.2 Concentration of Hibiscus rosa sinensis extract using forward
osmosis.
Soaked 4 hrs
Parameters Initial extract Final
concentrated
extract
Weight 500g 71g
pH 5.5 5.7
Anthocyanins 475.92 ± 1.4
ml/L
2279.39 ± 0.6
ml/L
TSS 3.3Brix 21.7 Brix

13. 4.2 Proximate analysis of Hibiscus rosa sinensis. 4.3 Anthocyanin contents
B 4.5 Ascorbic Acid
Parameters Fresh/dried flower
petals
Percentage
Moisture Fresh flower petals 85.19 ± 0.9
Dried flower petals 15.11 ± 0.5
Ash content Fresh flower petals 0.95 ± 0.03
Dried flower petals 5.46 ± 0.1
Acid insoluble Ash Fresh flower petals 0.18 ± 0.02
Dried flower petals 0.34 ± 0.03
Water soluble Ash Fresh flower petals 0.6 ± 0.02
Dried flower petals 1.25 ± 0.3
Protein Fresh flower petals 1.6 ± 0.04
Fat content Fresh flower petals 0.54 ± 0.06
Dried flower petals 1.14 ± 0.3
Sample Anthocyanin
(ml/L)
Fresh Petals 356.52 ± 0.2
Extract 475.92 ± 0.1
Concentrated
extract
2279.39 ± 0.3
Sample Ascorbic acid
(mg/100ml)
Fresh petals 34.88 ± 0.3
Extract 46.16 ± 0.4
Conc. Extract 93.03 ± 0.9

14. 5. CONCLUSION
The extraction of anthocyanins from the dried petals of Hibiscus rosa
sinensis has been done by using citrate phosphate buffer solution. To
increase the shelf life of the extract, concentration of extract is done
by using the forward osmosis method. Forward osmosis (FO) is a non-
thermal membrane technology that has energy efficiency, achieves
high concentration, high quality and recovery of the final product at
ambient pressure and temperature. The benefits of the forward
osmosis concentration are that it reduces weight as well as moisture,
and the shelf life of the extract increases when the moisture content is
reduced. For further extension of the shelf life of the extract and for
the convenient usage in food industry, spray drying method has been
adopted for the concentrated extract and converted into powdered
form, therefore it is easy to store, transport and convenient to use in
food products.

15. 6. REFERENCES
• Sadasivam, S., & Balasubramanian, T. (1987). Practical Manual in Biochemistry Tamil Nadu
Agricultural University. Purushothaman, A., Meenatchi, P., Saravanan, S., Sundaram, R., &
Saravanan, N. (2016).
• Quantification of total phenolic content, HPLC analysis of flavonoids and assessment of antioxidant
and anti-haemolytic activities of Hibiscus rosasinensisL. flowers in vitro. Int J Pharma Res Health
Sci, 4(5), 1342-1350.
• Missoum, A. (2018). An update review on Hibiscus rosa sinensis phytochemistry and medicinal
uses. J Ayu Herb Med, 4(3), 135-146.
• Ranganna, S. (1986). Handbook of analysis and quality control for fruit and vegetable products.
Tata McGraw-Hill Education.
• Trishitman, D., Negi, P. S., & Rastogi, N. K. (2021). Concentration of beetroot juice colorant
(betalains) by forward osmosis and its comparison with thermal processing. LWT, 145, 111522.