This is a summary of Flavor Chemistry in a shortest form

2. Types of Flavors
Thermally Induced Flavors
Stability in Food Systems
Effects of processing and Storage

3. Contents
Introduction
Types of Flavors
Thermally Induced Flaovrs
Stability in Food Systems
Effects of processing and Strage

4. Flavor Perception
Chemistry

5. Introduction
The perfume of a rose, the tang of an ocean breeze, the
aroma of a sizzling steak—tastes and smells, two of
our senses by which we characterize the world around
us. And yet, we can not adequately express, define, or
explain our taste and smell sensations. We can record
the sounds we hear, we can photograph the sights we
see, but we cannot store and retrieve the flavor of a
food or the scent of a flower except in and from our
mind.”
— Irwin Hornstein and Roy Teranishi, USDA

6. Importance
Flavor is one of the most important components responsible
for the overall sensory properties of taste and smell in any
food products (e.g., soft drinks). Among the many
organoleptic quality components, such as color,
rheological properties or packaging, flavor takes a
particular place through stimulating the odor and taste
receptors when eating. Therefore, flavor plays an
important role in consumer satisfaction, which will
subsequently drive consumers’ acceptance and influences
the continued consumption of foods. However, due to the
volatility and delicate properties of volatile flavor
compounds, they are unstable (Tan et al, 2014)

7. Flavor Perception
Gustatory, olfactory, and oral–somatosensory cues all
contribute directly to flavor perception
ISO 5492 1992:- Flavor as a “complex combination of the
olfactory, gustatory and trigeminal sensations
perceived during tasting.”
ISO 5492 2008 :- The flavor may be influenced by
tactile, thermal, painful and/or kinesthetic effects

8. Multisensory perception
Although, flavour is initially influenced by the receptors
in the eyes, nose, tongue and mouth lining, it is the
brain which interprets the overall sensation occurring
in the mouth (Taylor and Hort, 2004).

9. Smell
Aroma can be sensed orthonasally (i.e. sniffed through
the nostrils), or aroma compounds can reach the
olfactory receptors via the throat after the mastication
process, retronasally (Taylor and Hort, 2004).

10. Taste
The taste sensations of sweetness, sourness, bitterness,
saltiness and umami are detected by taste buds
located in the oral cavity. These taste buds are found
on the surface of the tongue in papillae. There are
four types of papillae, namely fungiform, filliform,
foliate and circumvallate papillae (Meillgaard et al.,
2007).

11. Touch
The sense of touch is divided into three different groups,
those being somesthesis, kinesthesis and chemesthesis
(Kemp et al., 2009). Somesthetic sensation percieves force
and particle size (Meilgaard et al., 2007). Nerve fibres in
muscles, tendons and joints sense tension and relaxation
kinaesthetically, giving rise to the perception of the
sensory attributes of hardness and heaviness (Kemp et al.,
2009). Chemesthesis is the chemical sensitivity of the skin
and mucous membranes, allowing for the perception of
hot, burning, tingling, cooling or astringent sensations
(Green, 2004). Although, some texture assessments are
performed visually, the main evaluation occurs in the
mouth (Cook et al., 2005; Van Vliet et al., 2009).

12. Sound
Sound is sensed by millions of tiny hair cells in the ear
that are stimulated by the vibrations from sound
waves (Kemp et al., 2009). The noise emitted by a
food during chewing or biting gives an indication of
the texture of the product, e.g. the crispness of a
lettuce leaf, the crunchiness of an apple (Verhagen
and Engelen, 2006). Acoustic emissions require a
crack speed of ~300-500m/s for foods to be perceived
as crispy (Luyten and Van Vliet, 2006).

13. Sight
Studies over the last 70 years or so have provided
empirical support for the claim that the color of a
food/drink can exert a powerful influence on people’s
flavor identification responses (e.g., DuBose et al.
1980; Hall 1958; Kanig 1955; Levitan et al. 2008; Moir
1936; Oram et al. 1995; Shankar et al. 2009; Stillman
1993; Zampini et al. 2007, 2008).

14. Guess?

15. Flavor Expectation based on Color
Green - Lime (69%), apple (20%), melon (11%)
Orange - Orange (91%), aniseed (5%), toffee (4%)
Yellow - Lemon (89%), pear (5%), apple (4%), melon (2%)
Blue - Spearmint (86%), raspberry (9%), cream soda (5%)
Gray - Blackcurrant (53%), licorice (40%), cherry (4%),
aniseed (4%)
Red - Strawberry (46%), raspberry (27%), cherry (27%)
Colorless - Flavorless (51%), cream soda (16%), vanilla (15%),
aniseed (15%), spearmint (2%), melon (2%), pear (2%)
Zampini et al. (2007)

16. Keasat et al, 2004

17. Flavour Sensation and Components
Anne Thierry
STLO, INRA Rennes
John Hannon
Teagasc Food Research Centre, Moorepark, Cork

18. The uniqueness of many flavor substances appears to
rely upon their ability to stimulate the olfactory
organ. (Stanly and Yan, 2000)

19. Chemistry
Flavor is caused by receptors in the mouth and nose
detecting chemicals found within food. These
receptors respond by producing signals that are
interpreted by the brain as sensations of taste and
aroma. Certain taste and aroma combinations are
characteristic of particular foods.
For example, a green apple tastes the way it does
because the unique combination of chemicals found
naturally within it are perceived by our mouths, noses
and brains as the distinct blend of sweet and sour
tastes and volatile aromas characteristic to the fruit.

20. Complex Chemistry
One natural flavor may contain hundreds or even
thousands of component substances, and some of
these substances are present in minute quantities.
For example, one of the nine key aroma compounds
found in pineapple is so potent that human subjects
can detect it at only 6 ppt—the equivalent of a few
grains of sugar in a 50m, 12 lane swimming pool.

21. Based on
Senses
Structure & Functional groups
Notes
Acceptability
Origin of Flavor Compound

22. Sense
Taste
Odour

24. History Recap
Aristotle postulated in 350 BCE that the two most
basic tastes were sweet and bitter.
Ayurveda, (5000BCE) an ancient Indian healing
science, has its own tradition of basic tastes,
comprising sweet, salty, sour, pungent, bitter
& astringent.
Ancient Chinese regarded spiciness as a basic taste.

25. Tastes
Bitter
Sour
Sweet
Salt
Ummami

26. Sour
H+
ions
Concentration is proportional to taste intensity among
inorganic ions
Organic ions are stronger than inorganic ions at same
concentration.
Intensity of taste depends on the potential of the acid
i.e. A weak acid taste as the same as a strong acid at same
concentration.
Ex : Acetic acid, Citric acid, Tartaric acid , Lactic acid,
gamma amino butyric acid (decarboxylation of glutamic
acid)

27. Salt
Na+
K, Ca & Mg salts of adipic, succinic, glutamic,
carbonic, lactic, hydrochloric, tartaric and citric acids.
Monopotassium phosphate, adipic and glutamic acids
and potassium sulfate.
Choline salt of acetic, carbonic, lactic, hydrochloric,
tartaric and citric acids.
Potassium salt of guanylic and inosinic acids
Sodium chloride is sweet at low (e.g., 0.020 M), but
salty at higher (0.050 M) concentrations.

28. Sweet
Lactose, Glucose, Maltose, Succrose
Glycerol
Mannitol, Maltitol, Xylitol
Ketones (after excercise)
Saccharine
Aspartame

29. Bitter
Phenolic compound
Cinnamic acid
Tannins to Green Tea
Glycocidic compounds
Nicotine to Pan Beetle Mix
Caffeine to Coffee
Alkali metals
Innorganic salts of Mg, Ca, NH4+ to hard water

30. Ummami
Glutamate
Glutamic acid
Specific ribonucleotides
Salts of glutamic acid
Salts of glutamate
MSG
KG
CaG

33. Structure
Esters
Linear terpenes
Cyclic terpenes
Aromatic
Amines

34. Esters
Geranyl acetate – Rose
Methyl acetate – sweet nail polish
Methyl propionate – Rum like
Methyl butyrate – pine apple
Ethyl acetate – wine
Ethyl butyrate – Orange
Isoamyl acetate – Banana
Pentyl butyrate – Pear
Pentyl pentanoate - apple

35. Linear terpenes
Compound Note Occurrence
Geraniol Rose/Flowery Lemon
Nerol Flowery Lemongrass
Citral Lemon Orange, Lime
Linalool Floral, sweet, woody Tea
Nerolidol Fresh bark Ginger

36. Cyclic compounds
Name Note Occurrence
Limoene Orange Orange, Lemon
Camphor Camphor Camphor laurel
Menthol Menthol Mentha
Carvone Caraway, Spearmint Caraway
Terpineol Lilac Lilac, Cajuput

37. Aromatic
Name Note Occurrence
Benzaldehyde Almond Almond
Eugenol Clove Clove
Cinnamaldehyde Cinnnamon Cassia, Cinnamon
Ethyl maltol Cooked fruit,
Caramalized
Cooked Fruits
Vanillin Vanilla Vanilla
Anethole Anise Sweet basil
Anisole Anise Anise
Thymol Thyme Thyme

38. Amine
Name Note Occurrence
Trimethyl amine Fishy aroma Milk
Putrecine Rotting flesh Rotting flesh
Pyridine Fishy Fish
Indole Fecal Flowery Fecal Jasmine
Skatole Fecal Feces

39. Functional Group
Alcohol – Furaneol, Menthol, cis-Hehanol
Aldehydes – Acetaldehyde, Cinamaldehyde,
Cuminaldehyde
Esters – Frutone, Ethyl methylphenylglycidate
Ketones - Oct-1-en-3-one (blood, metallic,
mushroom-like)
Lactones - gamma-Decalactone intense peach flavor
gamma-Nonalactone coconut odor
Thiols - Allyl thiol (2-propenethiol; allyl mercaptan;
CH2=CHCH2SH) (garlic volatiles and garlic breath

41. Oholf Classification

42. Natural
Artificial
Nature Identical

43. Natural Flavorings
The term natural flavor or natural flavoring means the
essential oil, oleoresin, essence or extractive, protein
hydrolysate, distillate, or any product of roasting,
heating or enzymolysis, which contains the flavoring
constituents derived from a spice, fruit or fruit juice,
vegetable or vegetable juice, edible yeast, herb, bark,
bud, root, leaf or similar plant material, meat,
seafood, poultry, eggs, dairy products, or
fermentation products thereof, whose significant
function in food is flavoring rather than nutritional.
(FDA)

44. Natural Flavoring
“Natural flavours” and “Natural Flavouring substances”
means flavour preparations and single substance
respectively, acceptable for human consumption,
obtained exclusively by physical processes from
vegetables, sometimes animal raw materials, either in
their natural state or processed for human
consumption.

45. Nature Identical
“nature-identical flavoring substances” means
substances chemically isolated from aromatic raw
materials or obtained synthetically; they are
chemically identical to substances present in natural
products intended for human consumption,
either processed or not. (FSSAI)
// Nature identical in EU but Artificial in US+

46. Artificial Flavoring
The term artificial flavor or artificial flavoring means
any substance, the function of which is to impart
flavor, which is not derived from a spice, fruit or fruit
juice, vegetable or vegetable juice, edible yeast, herb,
bark, bud, root, leaf or similar plant material, meat,
fish, poultry, eggs, dairy products, or fermentation
products thereof. (FDA)

47. Artificial Flavoring
“artificial Flavouring substances” means those
substances which have not been identified in natural
products intended for human consumption either
processed or not. (FSSAI)

48. Spices
The term spice means any aromatic vegetable substance
in the whole, broken, or ground form, except for
those substances which have been traditionally
regarded as foods, such as onions, garlic and celery;
whose significant function in food is seasoning rather
than nutritional; that is true to name; and from which
no portion of any volatile oil or other flavoring
principle has been removed.(FDA)

49. Maillard browning
Thermal degradation of THiamine

50. Maillard Browning
When aldoses or ketoses are heated in solution with
amines, a variety of reactions ensue, producing
numerous compounds, some of which are flavors,
aromas, and dark-colored polymeric materials, but
both reactants, disappear only slowly. The flavors,
aromas, and colors may be either desirable or
undersirable. They may be produced by frying,
roasting, baking, or storage.

51. MB
Amino acid + SugarMaillard reaction

57. Thiamine degradation

58. Thiamine
Thermal degradation of Thiamine produces Thiazoles

60. Introduction
long-term stability of flavor compounds in food product has
been a major concern in the food industry due to the
complex interactions between key food ingredients (e.g.,
polysaccharides and proteins). (Tan et al 2014)
Flavor release is defined as a flavor compound transport
process from the matrix to the vapor phase. Thus, a good
knowledge of the physicochemical interactions occurring
between flavor compounds and other major food
components is required for the control of food flavoring
and, more particularly, for understanding the phenomena
involved in the release of aroma compounds in the mouth.
In addition, the composition of the food matrix will
determine the extent and type of flavor compounds it is
inclined to bind.

61. Intro….
The variations of food components in different food
matrices have contribute significantly to different
interactions between the flavor compounds with
other food components, which consequently
influence the equilibrium headspace concentration of
flavor compounds

62. Interactions
Gum arabic, Xanthan gum – delayed flavour release
(Miehosseini et al 2008)
Fat content – Creamyness Smoothness Texture(Mao
et al, 2012 )
Protein – Reversible and irreversible binding of
volatile compounds

63. Interactions
Physical and Chemical Stability of Flavor
Effects and Interactions of Lipids with Flavor
Compounds
Effects and Interactions of Carbohydrates with Flavor
Compounds
Effects and Interactions of Proteins with Flavor
Compounds

64. Physical and Chemical Stability of Flavor
Compounds
Mechanisms of flavor perception
Concentration of flavor compounds in the receptors
Factors affecting partition and release of flavor
compounds in the mouth
Rate of volatilization
Physical and chemical states of flavor compounds in
foods
Binding behavior of flavor compounds
Factors affecting partition coefficients

65. Effects and Interactions of Lipids with Flavor
Compounds
 Increase flavor compounds adsorption and retention
 Decrease the partition coefficients
 Increase the flavor threshold concentration
Compounds Threshold Concentration (ppm)
Water Oil
Octanoic acid 5.8 350
ã-decalactone 0.05 3.0
Pentanal 0.07 0.3
Hexanal 0.03 0.05

66. Effects and Interactions of Carbohydrates with
Flavor Compounds
Soluble sugars increase the vapor pressures of volatile
compounds.
Polysaccharides stabilize flavor compounds in foods during
processing due to entrapment, adsorption, reduced mass
transport effects due to increased viscosity.
Cellulose adsorbs flavor compounds in intramolecular
region.
Amylose forms inclusion complexes with aliphatic flavor
compounds which fit inside the amylose helix.
The association constants with starch were 383, 930 and 2277
for limonene, methanol and decanal, respectively.

67. Effects and Interactions of Proteins with Flavor
The binding capacity of protein depends upon the
surface topography, porosity, and bulk density.
Proteins bind aldehydes and ketones to differing
extents, indicating differences in intrinsic binding
affinities, structural features of the protein,
differences in available surface area.

68. Effects and Interactions of Proteins with
Flavor
The Mechanisms of Flavor Compounds Interaction with
Protein
Scatchard equation
v/[L] = nK-vK
‘v’ is the number of moles of flavor compounds bound
per mole of protein.
‘L’ is the molar concentration of flavor compounds.
‘n’ is the total number of binding sites.
‘K’ is the intrinsic binding constant.

69. Effects and Interactions of Proteins with Flavor
Klotz equation
1/v = 1/n+1/nK[L]
A plot of 1/v vs. 1/[L]
Intercept = 1/n Slope = 1/nK

70. Stability of Flavor
Several mechanisms are involved in interaction of flavor
compounds with food components.
In lipid system, solubilization and rates of partitioning control the
interactions and partition coefficients, thus determine-s the
rates of release.
In polysaccharide system, polysaccharides interact with flavor
compounds by nonspecific adsorption and formation of
inclusion compounds.
In protein system, protein involves adsorption, specific binding,
entrapment, covalent binding and these mechanisms may
account for the retention of flavor compounds.
Moisture affects diffusion and partition coefficients and
macromolecular structures in the case of protein and
polysaccharides and thereby affect the rate of release of flavor
compound.

72. Processing
Thermal
Non thermal
HIPEF

73. Thermal Processing
In-Container Sterilization
Retortable pouch
Aseptic processing and Packaging
Rapid heating and Cooling
Pasteurization (LTLT, HTST,UHT)

74. Thermal Processing
Maillard Reaction
Furanones
Pyranones
Pyrolles
Thiopenes
Hydroxyacetone
Cyclotene
Dihydroxy acetone
Hydroxy acetal
Glyoxal
Pyruvaldehyde
Glycosaldehyde
Glyceraldehyde
Pyridines
Pyrazines
Oxazoles
Thiazoles
Pyrolles
Imidazoles

75. Thermal processing
Increase reaction kinetics and accelarates loss of
flavor compounds
Cooked/Heated/Burnt and stale flavor of milk is due
to ketones formation
Buttery, milky, coconut like flavors in milk are due to
lactones formation from thermal breakdown of
gamma and delta hydroxyacids

76. Thermal processing
Furan derivatives formed when casein is undergoes
browning reaction with fructose at T>90o
C
Acetol and Acetonin gives off flavor to milk which has
been heated above 90o
C
Chemical and rancid flavor increases in milk because
of increased amount of Butyric and hexanoic acids
which is treated above 100o
C
Hydrogen sulfide gives cooked flavor to milk and the
intensity linearly corresponds to the intensity of
heating.

77. Non Thermal Processing
High Pressure Processing
Pulse Electric Field
Pulsed X-Ray, Pulsed UV
Ohmic Heating, Radio Frequency, Microwave
Pulsed Light
Oscillating Magnetic Fields
Ultra Filteration
Irradiation

78. Irradiation
Meat
Roegg, bloody, fishy, brabecued corn, burnt, metalic, alcohol
or acetic acid
Radiolysis of water into free radical species is the reason
Garlic
Diallyl disulfide reduced significantly (9<0.05) when treated
with gamm radiation (wu et al, 1996)
Ginger
No major changes in volatile concentration in gamma
irradiated ginger
After 3 months decrease in a-zingiberene, B-bergamotene,
neral, geraneal and a-curcumene were significant (Wu and
Yang 1984)

79. HIPEF
40 kV/cm for 57 micro seconds
Reduces loss of flavor compounds during processing
compared to thermal pasteurization.
Compound 90o
C – 30s 35kV/cm – 200 us
Limoene 15% 60%
Ethyl butyrate 26% 82%
Adapted from (Jia et al., 1996)
Destruction of Orange Flavor Compounds

80. HIPEF
Ex: Study shows that the PEF-processed tomato juice
retained more flavor compounds of trans-2-hexenal, 2-
isobutylthiazole, cis-3-hexanol than thermally
processed or unprocessed control tomato juice (P <
0.05).
PEF-processed juice had significantly lower non
enzymatic browning and higher redness than thermally
processed or control juice (P < 0.05). Sensory
evaluations indicated that the flavor of PEF-processed
juice was preferred to that of thermally processed juice
(P < 0.01).

81. Storage
Packaging material interaction
Temperature (RT, Chilled, Refrigerated, Frozen)
Time
Vacuum
MAP

82. Effects of Packaging Materials
Residual compounds Interactions
Diffusivity of volatile flavor compounds
Sorption of flavor compounds by packaging material
Case: Orange Juice in
 Low Density Poly Ethylene (LDPE)
 Polyethylene Terephthalate (PET)
 Polyvinylidine Chloride (PVC)
 Ethyl vinyl alchol copolymers (EVOH)

83. Experiment
D-Limoene
Alpha-pinene
Ethyl butyrate
Octanal
The sorption of these compounds were measured
during storage.

84. Results
LDPE sorbed greater Limoene and pinene than other
packages (P<0.5)
PET sorbed 30% less limonene than LDPE (p<0.5)
PVC sobed 50% less limoene and pinene sorption
than LDPE (p<0.5)
Ethyl butyrate and octanal sorptions were not
different for all packaging materials (p<0.5)

85. Time
All initial flavor compounds depletes with time
Certain Off-Flavor compounds increases with time
Lipid oxidation and rancid flavor
Weibull and PLSR distribution models suitable for
predicting retention of flavor compounds with time of
storage.
Stale flavor from casein is from formation of carbonyl
compounds.
Benzaldehyde

86. Low Temperature
Allin content in garlic has been recorded to increase
when stored at 4o
C

87. References
1. A Taste For Flavour Characterization, Laboratory
Newshttp://www.labnews.co.uk/features/a-taste-for-
flavour-characterisation
2. Andrew J. Taylor, Robert Linforth., Food Flavour
Technology., John Wiley & Sons,2009.
3. Arie J. Haggen Smit., The Chemistry Of Flavour.,
Engineering and Science Monthly., 1949.
4. Arielle J. Johnson, Gregory D. Hirson, Susan E. Ebeler.,
Perceptual Characterization and Analysis of Aroma
Mixtures Using Gas Chromatography Recomposition-
Olfactometry., PLoS ONE. 2012

88. References
6. Barbara d’Acampora Zellner , Paola Dugo, Giovanni
Dugo, Luigi Mondello, Gas chromatography–
olfactometry in food flavour analysis, Journal of
Chromatography A, Science Direct, 2007.
7. Bethany J. Hausch., Flavor Chemistry Of Lemon-Lime
Carbonated Beverages., University Of Illinois,
Urbana Campaign, 2010
8. Dr. David B. Min., Flavor Chemistry.,Ohio State
University., Lecture., 2008
9. Factors affecting retention and release of flavour
compounds in food carbohydrates., Naknean, P. and

89. References
10. Fatma A. M. Hassan, Mona A. M. Abd El- Gawad, A. K. Enab.,
Flavour Compounds in Cheese (Review)., Research on Precision
Instrument and Machinery., 2013.
11. Gary Reineccius., Sourcebook of Flavors.,Springer Science &
Business Media, 1998. H.-D. Belitz · W. Grosch · P. Schieberle,
Food Chemistry, Springer 2009
12. Identification of Potent Odorants in a Novel Nonalcoholic beverage
Produced by Fermentation of Wort with Shiitake (Lentinula edodes)
13. Jida Zhang, Gang Cao, Yunhua Xia, Chengping Wen, Yongsheng Fan,
Fast analysis of principal volatile compounds in crude and
processed Atractylodes macrocephala by an automated static
headspace gas chromatography-mass spectrometry, Pharmaconosy
Magazine, Vol 10, Isseue 39, 2014

90. References
14. Jon G. Wilkes, Eric D. Conte, Yongkyoung Kim, Manuel Holcomb, John B.
Sutherland, Dwight W., Miller., Sample preparation for the analysis of flavors
and off-flavors in foods, Journal of Chromatography A, Elsevier, 2000.
15. Katherine A Thompson Witrick., Characterization of aroma and flavor
compounds present in lambic (gueuze) beer., Virginia Polytechnic Institute
and State University., 2012
16. Kathrin Ohla, Ulrike Toepe, Johannes le Coutre, Julie Hudry., Visual-
Gustatory Interaction: Orbitofrontal and Insular Cortices Mediate the Effect of
High-Calorie Visual Food Cues on Taste Pleasantness., PLoS ONE 2012.
17. Małgorzata Biniecka, Sergio Caroli., Analytical Methods for the qualntification
of volatile aromatic compounds., Trends in Analytical Chemistry., 2011.

91. References
17. Malika Auvray and Charles Spence., The
multisensory perception of flavor., Conciousness and
Cognition., Elsevier 2008.
18. Maria E.O. Mamede a, Gla´ucia M. Pastore; Study of
methods for the extraction of volatile compounds
from fermented grape must; Journal of Food
Chemistry; 2005.
19. Mariaca R., Bosset J.o., Instrumental Analysis of
volatils (flavour) compounds in milk and dairy
products(a review)., Swiss federal dairy research
station., 1997.

92. References
21. Michael H. Tunick , Susan K. Iandola and Diane L. Van Hekken.,
Comparison of SPME Methods for Determining Volatile Compounds
in Milk, Cheese, and Whey Powder., Foods., 2013.
22. Michael Moss, The Newyork Times, The Extraordinary Science of
Addictive Junk Food,
http://www.nytimes.com/2013/02/24/magazine/the-extraordinary-
science-of-junk-food.html?pagewanted=all&_r=0
23. Naknean, P. and Meenune, M., Factors affecting retention and
release of flavour compounds in food carbohydrates., International
Food Research Journal., 2010.
24. O.Bensebia , D.Barth, A.Dahmani Supercritical Carbon Dioxide
Extraction Of Rosemary Comparison With Steam Distillation And
Hydrodistillation., University Of Algeria. 2005

93. For their kind help

94. Thank you!!!
Dr.K.Aparna, Assistance Professor – Dept of Food and
Nutrition,, PG&RC, PJTSAU.
Socialist Democratic Secular Govt of India and ICCR,
For their courtesy of Sponsoring me to study here.
PJTSAU, Central Library. For lending Books and
Internet fascility
My Class Mates.
You all for your kind attention

96. Questions
Please!!!