This document provides information about grapefruit/pomelo, including its composition, health benefits, and extraction methods. Grapefruit contains nutrients like vitamin C and flavonoids. It has potential health benefits such as reducing risk of heart disease and cancer. Grapefruit extracts can be used in food industries as antimicrobial agents to improve food safety and shelf life. Various extraction methods are discussed, including cold-pressing, GC-MS, and HPLC, to extract compounds from grapefruit peel, pulp, and seeds. Factors like pH, time, and temperature affect the extraction process.

1. Ateeqa Ijaz 19-21013
Dr. M.Bilal Sadiq
Grapefruit/Pomelo

2. TABLE OF CONTENTS
FAOSTATS…………………………………………………………………………….. 2
INTRODUCTION………………………………………………………………………. 3
COMPOSITIONAL ANALYSIS……………………………………………………… 4
BENEFITS OF GRAPEFRUIT/POMELO …………………………………………. 5
SIGNIFICANCE IN FOOD INDUSTRIES
SUBSTRATE FOR ENZYMES PRODUCTION
HEALTH BENEFITS
AROMATHERAPY
EXTRACTION METHODS………………………………………………………… 6
COLD-PRESS METHOD
TDS-GC-MS METHOD
HPLC-DAD-ESI-MS/MS
EZYMATIC EXTRACTION (DIAGRAM)
FACTORS CONSIDERATION…………………………………………… 8

3. FAOSTATS

4. INTRODUCTION
Citrus paradisi commonly known as grapefruit one of the significant fruit among different
citrus varieties having a lot of benefits. According to the Megan ware it is an excellent source
of vitamin A and C and helps in decreasing the risk of heart diseases, obesity, diabetes and
overall mortality rate. In addition to the vitamin A and C it also contains small amount of
vitamin E, thiamine, niacin, phosphorus, manganese, zinc, panthonic acid, riboflavin and
potassium but in very small amount thus aiding the anti-oxidant properties of the fruit and its
products.
Its pulp, peel, seeds and juices are full of beneficial components for example, vitamins,
organic acids, volatile, non-volatile compounds, flavonoid etc. It is usually eaten as fresh fruit
however; it can be stored as well. In addition to its specialty to be rich in vitamin C, its peel
and leaves are full of essential oil adding to its health and aroma-therapeutic benefits.
Furthermore, it could serve a lot of functions in pharmaceutical, aromatherapy and in food
industries as well (Phi et al., 2015). Following are the main compounds found in the essential
oils extracted from the peel of the grapefruit:
 Sabinene
 B- pinene
 Myrcene
 A-terpineene
 Limonene
 Terpinolene
 Linalool
 Γ-terpinene
These essential oils have antioxidant and antimicrobial activities. They prove to be effective
against P. chrysogenum and P. verrucosum as a mold inhibitor whereas in the case of
bacteria, it proves to be effective against P. expansum, B. cereus, F. solani and A. flavus.
(Viuda-Martos et al., 2008; Choi, 2010; Hung et al., 2013; Lan-Phi et al., 2015). The d-
limonene a dietary component found in the peel of citrus fruits according to a study shows
protective effects against human cancer. In addition to this grapefruit has a lot of health
benefits.

5. In laboratory it can be extracted using steam distillation. The volatile components like
aldehydes, monoterpenes, alcohol and esters can be isolated by coupled gas chromatography
and mass spectrometry (Ivoke N et al., 2013). However, there are certain other methods to
extract volatile and non-volatile compounds (sugars & organic acids). These methods include
solvent extraction, headspace solid phase microextraction, solvent-free microwave extraction
SFME, hydrodistillation which is then further identified using techniques gas
chromatography-mass spectrometer and flame ionization detector (Cheong et al.,2012 ; Uysal
et al., 2011). Some of the organic acids i.e. ascorbic acid can be extracted through various
titration methods like iodometric and dye titration at laboratory scale (Shrestha et al., 2015).
COMPOSITIONAL ANALYSIS:
Grapefruit is full of nutritional value with 59% of it is enriched in vitamin C remaining
contains fiber, panthothenic acid, copper, vitamin A, biotin, B1 are also present in it. It is full
of bioactive compounds of which flvanoids are the most important. Major of the flavonoids
includes didymin naringenin, hesperetin and narirutin (Hung et al., 2016). Following are the
list of phytochemicals found in the grapefruit juice (Uckoo et al.,2012).
Flavonoids
 Narirutin
 Naringin
 Hesperidin
 Neohesperidin
 Didymin
 Poncirin
Limonoids
 Limonin
Furocoumarins
 DHB
 Bergamottin
 5-M-7 GC
Organic Acid
 Citric acid
 Ascorbic acid
BENEFITS OF GRAPEFRUIT/POMELO
FOOD INDUSTRIES:
Food industries are growing enormously with an increase in a need of its safety. In the past
few years several antifungal and antimicrobial based films have been developed in order to
improve the shelf life and to reduce the practice of chemical preservative. Moreover, the
demand for biodegradable, eco-friendly and naturally formulated packaging has been
increased. This demand has been aided through the various researches in the emerging field
of food technology. The use of grapefruit seed extract with chitosan based composite film
will extend the shelf-life by preventing fungal growth with the concentration range of 0.5-1.5

6. % v/v. In addition to that it also delays the incidence of fungal growth thus increasing the
shelf-life of bread by two folds. Furthermore, it is not only restricted to anit-fungal but the
packaging itself is biodegradable thus fulfilling the rising demand of eco-friendly safe food
packaging (Tan et al., 2014). Corn Starch-chitosan blend film also shows effectiveness
against certain gram positive and gram negative bacteria ( Bof et al., 2016).
The grapefruit seed extract when combined with red algae film helps to prevent the growth of
certain bacteria. This film when wrapped on cheese and bacon prevent the growth of Listeria
monocytogenes and Escherichia coli 0157:H7. Therefore, increasing the food safety and
quality with an addition to favor environment due to biodegradable property (Shin et al.,
2011). Following table shows the anti-microbial activity of grape food seed extract provided
by Shin et al. in context with the different concentration GSE per gram in combination with
red algae wraps.
GSE
(g)
Inhibition zone mm
Escherichia coli 0157:H7 Listeria monocytogenes
0.5 13.0±0.49 28.0±0.41
0.7 13.6±1.04 27.9±1.53
1.0 15.8±0.97 29.8±1.50
1.2 16.4±2.06 32.5±0.77
The ready to eat fresh fruit is another increasing demand of consumers but such products are
prone to various sources of pathogenic bacteria due to semi-permeable packaging. GSE has a
lot of anti-microbial and ant-fungal properties and can serve to deal this challenge as well.
The use of GSE and GSE in combination with nisin and citric acid could prove to effective
preservative with no toxicity (Xu et al., 2006).
SUBSTRATE TO PECTINASE ENZYME PRODUCTION:
Peel of pomelo fruit contains lignocelluloltyic material including pectin which serves as a
substrate for the production of pectinase enzyme. These peel when used as a solid substrate
with appropriate parameters pectin production from Aspergillus niger LFP-1 cause a large
increase in the production (Darah et al., 2013).
HEALTH BENEFITS:

7. Grapefruit possess a lot of health benefits significantly anti-obesity, anti-inflammatory and
anti-cancer even. Flavonoids are consider to be the most significant in terms as these
phytochemical compounds exhibit various health activities however, many studies reported
its ill effects when interacted with certain medications. Despite of its interaction with
medications the biological activities of the compound furanocoumarins have anti-
inflammatory, anti-oxidative, anti-genotoxitic, anti-proliferative and neuroprotective
activities. Furthermore, this possess anticancer activities against various from of it like breast
cancer, skin cancer etc. and also plays a pivotal role for bone enhancement but in-vitro
studies related to its anticancer properties still needs some comprehensive researches (Hung
et al., 2016).
AROMATHERAPY:
The aromatherapy is significant in reducing the anxiety, stress, fatigue and depression as
well. The essential oils aroma therapy of grapefruit proves to be effective in reducing the
anxiety during the colonoscopy of the patients (Hozumi et al., 2017). Hence it can be used to
engage the patients in care.
EXTRACTION METHODS
COLD-PRESSING EXTRACTION METHOD
Cold-press method also known as scarification method is one of the best method for the
extraction of essential oils and can be used to extract them from pulp, seeds and peels as well.
It is a mechanical method for the extraction at reduced heat and minimized temperature. Lan-
Phi et al., in his article “Chemical composition, antioxidant and antibacterial activities of
peels’ essential oils of different pomelo varieties in the south of Vietnam.” Used the similar
method for the for the extraction of essential oils from the peel of pomelo He extracted it by
hand pressing from the flavedo eventually obtaining it in the brine solution. Further the
analysis of composition was done through gas chromatography ( GC) and GC-MS. Silica gel
column was used to fractionate the volatile compounds present (Phi et al., 2015; Phi et al.,
2006).
TDS-GC-MS METHOD
For the extraction of volatile compounds TDS-GC-MS method was used by Shao et al., 2014.
This is an innovative methods for determination and extraction of volatile compounds in its

8. natural state from the peel. In this method the peel was firstly chopped into fine small pieces
and put into the air bag. The air was removed and purified through activated carbon filter.
Afterwards a TDS3 instrument was used in coupled with GC-MS for the further analysis. The
quantitative and qualitative data was then analyzed using Xcalibur software (Shao et al.,
2014).
HPLC-DAD-ESI-MS/MS
The other methods include HPLC-DAD-ESI-MS/MS for the extraction of flavonoids.
Narangin was extracted using this method by Zhang et al., 2011 in which they have prepared
samples using domestic sequeezer and converted into powder. It was then stored at 40 C prior
to further analysis. Analysis was done through HPLC-MS analysis.
EZYMATIC EXTRACTION (DIAGRAM)
The following figure taken from “Enzyme-assisted extraction of bioactives from plants”
shows the method of bioactive compound extraction( Puri et al.,2012)
OTHER

9. FACTORS CONSIDERATION
In a study “Pomelo (Citrus maxima) pectin: Effects of extraction parameters and its
properties” several factors have been discussed that effects the extraction capabilities with
respect to the extraction of pectin enzyme. They states that pH, time, solid/solvent ratio and
temperature plays a crucial role on the extraction properties as well as rheological properties
of extract. pH is the most significant in this case as it affects the composition of side chain of
monosaccharides and the overall yield of pectin. However, these factors do not affect the DE
of the extract.
Conclusion:
Grapefruit on the whole is very beneficial; not only its pulp gives us nutritious and health
benefits but its peel and seeds have a lot of benefits as described above. If utilized properly it
could unlock a lot of doors in food technology, pharmaceutics, in health field and even in
cosmetics industry. However despite of a lot of researches in this context it still need more
researches.

10. References
 Bof, M. J., Jiménez, A., Locaso, D. E., García, M. A., & Chiralt, A. (2016). Grapefruit
Seed Extract and Lemon Essential Oil as Active Agents in Corn Starch–Chitosan Blend
Films. Food and Bioprocess Technology,9(12), 2033-2045. doi:10.1007/s11947-016-
1789-8
 Darah, I., Taufiq, M. M., & Lim, S. H. (2013). Pomelo Citrus grandis (L.) osbeck peel as
an economical alternative substrate for fungal pectinase production. Food Science and
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 Figure 2f from: Irimia R, Gottschling M (2016) Taxonomic revision of Rochefortia Sw.
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https://doi.org/10.3897/BDJ.4.e7720. (n.d.). doi:10.3897/bdj.4.e7720.figure2f
 Figure 2f from: Irimia R, Gottschling M (2016) Taxonomic revision of Rochefortia Sw.
(Ehretiaceae, Boraginales). Biodiversity Data Journal 4: E7720.
https://doi.org/10.3897/BDJ.4.e7720. (n.d.). doi:10.3897/bdj.4.e7720.figure2f
 Figure 2f from: Irimia R, Gottschling M (2016) Taxonomic revision of Rochefortia Sw.
(Ehretiaceae, Boraginales). Biodiversity Data Journal 4: E7720.
https://doi.org/10.3897/BDJ.4.e7720. (n.d.). doi:10.3897/bdj.4.e7720.figure2f
 Figure 2f from: Irimia R, Gottschling M (2016) Taxonomic revision of Rochefortia Sw.
(Ehretiaceae, Boraginales). Biodiversity Data Journal 4: E7720.
https://doi.org/10.3897/BDJ.4.e7720. (n.d.). doi:10.3897/bdj.4.e7720.figure2f
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