15-minor components Flashcards
what is nutraceutical?
a product isolated or purified from foods that is generally sold in medicinal forms not usually associated with food.
2 analysis of nutracetuical
1.1- Analysis of phenolic compounds 1.2- Analysis of pigments and colorants
A nutraceutical is demonstrated to have ?
a physiological benefit or provide protection against chronic disease.
e.g of nutraceutical
phenolic compounds, some fatty acids and some peptides).
e.g of nutraceutical
resveratrol EGCG ECG curcumin EGC EC
what is phenolic compounds
substance that consists of an aromatic ring linked to one or more hydroxyl groups, including Functional derivatives (esters, methyl ethers, glycosides etc.).
More than ____polyphenolics, including over ____flavonoids have been identified, and the number is still growing.
8000
4000
-Phenolic compounds can be divided to four major groups？ list
phenolic acid
flavonoids
tannins
stilbene&lignan
what does flavonoid contain
2 phenol groups with one heterocyclic linkage
what is the Importance of Phenolic compounds (and their assessment) in food:
- Polyphenols can influence food quality negatively or positively
phenolic compound has ___ activity? how?
antioxidant -due to phenol part
scavenging free radical
phenolic affect on health?
reduce coronary heart disease risk and some cancer type
Phenolic acids have been associated with __,___ and nutritional and antioxidant properties of foods.
color, sensory qualities
The food industry has investigated the content and profile of phenolic acids, their effect on ___, ___, and their roles as ___.
fruit maturation, prevention of enzymatic browning, and their roles as food preservatives.
Food manufacturers are always trying to improve food quality (e.g. ___, __, and ____) through either __ or ____ some substances that can reduce or enhance food quality.
(e.g. sensory attributes, nutritional, and microbial quality) through either preventing or allowing formation
phenolic compound inhibit ___ in various food such as raw and cooked meat, poultry products and fish.
lipid oxidation
Polyphenols, in some fruits and vegetables, can be converted ____to____, and leads to loss of ___, ____ and ____ of food.
enzymatically to brown pigments, and this enzymatic browning leads to loss of nutritional, functional quality of food.
high levels of polyphenols are responsible for ____and for ____
enzyme-catalysed discoloration in different cheeses
undesirable flavour
Polyphenols can bind __, __, and ___ digestibility.
proteins, carbohydrates
reduce
4 method to determine phenolic compound
- spectrophotometric
- chromatographic
- NIR near infrared FT-IR
- MS-mass spectroscopy
There is an increasing demand for highly ___and ___ analytical method for the determination of polyphenols.
sensitive
selective
Chromatographic techniques ( used in __?
separation, qualitative and quantitative
analysis).
e.g of Spectrophotometric method
Folin–Ciocalteu assay
4 ex of chromatographic?
- 1- High Performance Liquid Chromatography (HPLC). 2.2- HSCCC (High Counter Current Chromatography). 2.3- Supercritical Fluid Chromatography (SFC).
- 4- Other Chromatographic techniques( e.g. TLC).
FC assay belong to?
Spectrophotometric methods
polyphenol react with ___ to form a___ complex that can be quantified. FC method is based on a ___ by phenolic compound
specific redox reagent
blue
chemical reduction of FC reagent
phenolic compound+ FC reagent–>
blue complex
FC steps
1- Place 1 ml sample, a gallic acid calibration standard in 100-ml volumetric flask.
2- Add 70 ml water
3-Add 5 ml FC reagent.
4- incubate 5min at room temperature.
5- Add 15ml sodium carbonate (Na2CO3).
6- Add water to the 100-ml line, and incubate for 2hr.
7- measure the blue solution at 765nm.
Chromatographic technique use in?
separation, qualitative and quantitative analysis
HSCCC:separation between ___ phases by use of __ or _____during __of two liquid phases
separation between two liquid phases by use of centrifugal or counter current during mixing of two liquid phases
extract phenolic compound before/after using chromatographic technique
before
Extraction is very important step in the ___ , ___ and use of phenolic compounds and there is/isn’t single and standard extraction method.
isolation , identification and use of phenolic compounds and there is no single and standard extraction method.
what is liquid-liquid extraction?
It is a mass transfer operation in which a liquid solution initially containing one or more solutes is thoroughly mixed with an immiscible or nearly immiscible liquid (solvent).
liquid-liquid: The solvent exhibits preferential ____ toward one or more
of the components in the and has different ___.
affinity or selectivity
density.
Solvent containing the compound of interest is later/before separated from the feed solution.
later
what is solid-liquid extraction?
It can be defined as a mass transport phenomenon in which compounds contained in a solid matrix migrate into solvent brought into contact with the matrix.
Mass transport phenomena can be enhanced by?
changes in concentration gradients, diffusion coefficients or boundary layer.
what does s-l used to?
recover important food components: sucrose in cane or beets, lipids from oil seeds, proteins in oil seed meals, polyphenolic compounds from plants, fruits, and vegetables.
SFE is based on?
close to the critical point, the solvent changes its properties rapidly with only slight variation of pressure.
The most utilized fluid has been?
supercritical carbon dioxide ( SC-CO2).
adv of SFE?
Automated and friendly to the environment.
other extraction methods?
Enzymatic Hydrolysis and ultrasonic.
catechines: flow rate temp
mobile phase
stationary phase
1ml/min
35oC
15%/80%ACN ,2%acetic acid
4.6mmx250mm, 5um
why color is important characteristic of food?
color: fruit immature,ripe?
based on first impression, a judement is made about wether food is safe or taste good?
why color is added to food?
(1) to replace color lost during processing,
(2) to enhance color already present,
(3) to minimize batch-to-batch variations,
(4) to color otherwise uncolored food.
food color divided into 4 categories?
(1) natural colors, (2) nature-identical colors, (3) synthetic colors, and (4) inorganic colors.
ex of natural pigments
anthocyanin
carotenoid
chlorophyll
what is anthocyanin
flavonoid compounds that produce plant colors ranging from orange and red to various shades of blue and purple.
what is carotenoid?
are lipid-soluble, yellow-orange-red pigments found in plant. (e.g. carotenes, lycopene, lutein, annatto, paprika, saffron).
what is chlorophyll?
is the lipid-soluble, green pigment found in plant. (e.g. carotenes, lycopene, lutein, annatto, paprika, saffron).
lutein: belong to? color?
yellow
carotenoid & falvonoid
e.g. egg yolk
anthocyanin e.g. color
lycopene
red
The polar character of the anthocyanin molecule allows for?
its solubility in many solvents such as alcohols, acetone, dimethyl sulfoxide, and water.
The choice of extraction method should consider?
maximize pigment recovery with a minimal amount of adjuncts and minimal degradation or alteration of the natural state.
steps of analysis anthocyanin
1- Extraction, 2- Purification, 3- Measurement.
In this method,___extracts the anthocyanins from the plant material, and ___ further isolates and partially purifies the pigments.
acetone
chloroform
- The addition of chloroform results?
phase separation between the aqueous portion and the bulk phase
aqueous-water soluble
bulk phase- __?
nonpolar compounds
write down extraction step
1-Mix (50g) powdered plant material with acetone.
2- Separate the anthocyanin extract (filtrate) from insoluble plant material by a filter paper.
3- Reextract plant material with 70% (v/v) aqueous acetone until a clear or faintly colored solution is obtained.
4- Transfer filtrate to a separatory funnel, add chloroform, and gently mix by turning funnel upside down a few times.
5-Store sample overnight at 4°C or until a clear partition between the two phases is obtained.
6- Purify the extract using column chromatography
purification: water with 0.01%HCL
ethyl acetate
methanol with 0.01%HCL
sugar acid
phenolics
anthocyanins
1-UV-Visible Spectroscopy (pH-differential method).
is based on
structural transformation of the anthocyanin chromophore as a function of pH, which can be measured using optical spectroscopy.
The pH-differential method is a rapid and easy procedure for the quantitation of ___anthocyanins.
monomeric
The pH-differential method is permits accurate and rapid measurement of the____, even in the presence of polymerized degraded pigments and other interfering compounds.
the total anthocyanins
-Anthocyanin pigments undergo _____with a change in pH manifested by strikingly different absorbance spectra. The colored oxonium form predominates at pH __and the colorless hemiketal form at pH __
reversible structural transformations
1.0
pH 4.5.
oxonium form: which color?
orange to purple
ph=1
quinonoidal base color? ph?
ph=7
blue
hemiketal form: color, ph
4.5
colorless
chalcone color, ph
colorless
4.5
