CONCENTRIC ENCAPSULATION OF LYCOPENE AND OMEGA FATTY ACIDS
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Date
2019
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DIVISION OF FOOD SCIENCE AND POSTHARVEST TECHNOLOGY ICAR-INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI
Abstract
A study was undertaken to achieve concentric encapsulation of lycopene and
ω-fatty acid (rice bran oil) using suitable techniques. Entrapment of lycopene from
grapefruit and papaya into rice bran oil (RBO) was achieved using two methods, (i)
Supercritical-CO2 (SC-CO2) extraction of lycopene from grapefruit and papaya
matrices using rice bran oil as a co-solvent and (ii) Supercritical-CO2 extraction of
lycopene from grapefruit and papaya matrices using ethanol as a co-solvent and
subsequently encapsulating it into rice bran oil using high pressure homogenization.
Rice bran oil encapsulating the lycopene obtained from both the aforesaid methods
were subsequently encapsulated using a combination of polysaccharide (from
jackfruit seed & tapioca) and protein concentrate (from whey & soybean) using spray
drying technique.
SC-CO2 extraction of lycopene from grapefruit (cv. Red Blush) and papaya
(cv. Red Lady) matrices with RBO as a co-solvent was separately optimized with
temperature, pressure, and time of extraction as independent variables. The flow rates
of SC-CO2 and RBO were fixed at 35g/min. and 1g/min. respectively. Extraction of
lycopene from lyophilized powder of grapefruit and papaya were optimized. Each of
the independent variables were used with five levels (pressure 250, 300, 375, 450 &
500 bars; temperature 55, 60, 70, 80 & 85°C; and extraction time 60, 90, 135, 180 &
210 min.) for experimentation using a central composite rotatable design (CCRD) of
response surface methodology. Twenty experimental runs were carried out for each of
the two lycopene matrices i.e. grapefruit and papaya. Responses were analyzed using
Design Expert software for maximization of lycopene extraction efficiency and
retention of γ-oryzanol content in oil. For the extraction of lycopene from grapefruit
the optimum combination of independent variables were 325 bars, 64°C, and 143 min.
and for that of papaya the same were 354 bar, 67°C, and 130 min. At the optimum
conditions lycopene recoveries of 70.52 ± 3.65% and 79.27 ± 1.69% and γ-oryzanol
content of 11154 ± 148 ppm and 11079 ± 146 ppm were predicted. For validation of
the predicted values two set of experiments at the optimum condition with three
replications were carried out. Average of the experimental lycopene recoveries
obtained were 70.66 ± 3.02% and 78.81 ± 1.78%; and those for γ-oryzanol content
were 11099 ± 186 ppm and 10984 ± 190 ppm.
Ethanolic extract of lycopene from grapefruit and papaya matrices using SCCO2 were separately encapsulated using high pressure homogenization (HPH) with
whey protein concentrates (WPC) or soy protein concentrates (SPC) respectively as
emulsifiers. Oil in water emulsion formulation for both the cases were designed using
central composite design (CCD) with five levels each of respective emulsifier
concentration (WPC/SPC) 0.25, 0.5, 0.75, 1.0 and 1.25% w/v; pressure of
homogenization 10000, 15000, 20000, 25000 and 30000 psi; and number of passes
through the homogenizer 1, 2, 3,4 and 5). A total of 20 experimental runs were
conducted for each of the two sets and conditions were optimized based on
maximization of emulsification efficiency and γ-oryzanol content; minimization of
average particle size, polydispersity index. Oil content in pre-emulsions was kept
constant at 6%, w/v in all the experimental runs. The optimum combinations of
independent variables for encapsulation of lycopene extracted from grapefruit into
RBO were 0.9% emulsifier concentration, 21000 psi homogenization pressure and 2
passes through the homogenizer. The same for encapsulation of lycopene extracted
from papaya into RBO were 1.0%, 19000 psi and 3 respectively. At the optimum
conditions emulsification efficiencies were 92.18 ± 1.89% and 87.37 ± 3.12%; γoryzanol content were 11141 ± 162 ppm and 10985 ± 144 ppm; average particle size
167 ± 25 nm and 390 ± 18 nm; and polydispersity index 0.20 ± 0.015 and 0.24 ±
0.032; and ζ-potential were -36.7 ± 1.25 mV and -39.2 ± 1.29 mV respectively. In
fact, ζ-potential for all forty experimental runs was found to be below -30 mV
indicating excellent emulsion stability.
The optima obtained for emulsification of lycopene extracted from grapefruit
using WPC as an emulsifier was used for the emulsification of lycopene extracted
from papaya. The emulsified lycopene extracted from papaya using WPC as an
emulsifier had an emulsification efficiency of 92.09 ± 2.06%, γ-oryzanol of 11128 ±
183 ppm, average particle size of 161 ± 27 nm, polydispersity index of 0.20 ± 0.016
and ζ-potential of -36.41 ± 1.41 mV. Similarly, emulsification of lycopene extracted
from grapefruit was tried using the optima obtained for emulsification of lycopene
extracted from papaya with SPC as an emulsifier. The emulsion so obtained was
found to have an emulsification efficiency of 87.93 ± 3.50%, γ-oryzanol of 11010 ±
162 ppm, average particle size of 390 ± 20 nm, polydispersity index of 0.24 ± 0.036
and ζ-potential of -38.69 ± 1.47 mV. Non-significant differences between all the
responses for lycopene extracted from both grapefruit and papaya with use of similar
emulsifier (WPC/SPC) clearly indicated that the source of lycopene did not have any
effect on the emulsification process.
Lycopene extracted from grapefruit and papaya matrices using SC-CO2 as
solvent and RBO as co-solvent were each separately encapsulated with four different
combinations of protein and polysaccharide i.e. Whey Protein Concentrate (WPC) &
Jackfruit Seed Polysaccharide (JSP); Soy Protein Concentrate (SPC) & JSP; WPC &
Tapioca Polysaccharide (TP); and SPC & TP by spray drying. Additionally, emulsion
obtained using lycopene from grapefruit with WPC as an emulsifier was encapsulated
using two different wall materials (WPC+JSP and WPC+TP); emulsion obtained
using lycopene from grapefruit with SPC as an emulsifier was encapsulated using two
different wall materials (SPC+JSP and SPC+TP); emulsion obtained using lycopene
from papaya with WPC as an emulsifier was encapsulated using two different wall
materials (WPC+JSP and WPC+TP); and emulsion obtained using lycopene from
papaya with SPC as an emulsifier was encapsulated using two different wall materials
(SPC+JSP and SPC+TP). A total of 16 spray dried products were obtained each with
three replications (a total of 48 experimental runs). Protein to polysaccharide ratio
was kept at 1:2.6, 1:2.2, 1:3 & 1:2.6 for combination of WPC+JSP, WPC+TP,
SPC+JSP & SPC+TP respectively. The total solids (lycopene + oil + wall material) in
the spray feed was kept constant at 30% w/v, oil concentration at 20% of the total
solids and inlet air temperature at 140°C for all the spray drying experimental runs.
The final product was evaluated with respect to their lycopene retention, γ-oryzanol
retention, average particle size, peroxide value and antioxidant activity. Lycopene
retention in microcapsules was varied from 89.53 to 97.02%, γ-oryzanol retention
from 91.75 to 99.47%, average particle size from 31 to 72 µm, peroxide value from
0.99 to 1.37 meq/kg and antioxidants activity from 461 to 498 µmol TEAC/g.
In vitro release behaviour of γ-oryzanol and lycopene from microcapsules
prepared using spray drying was studied under simulated gastro-intestinal conditions
for a total period of 8 h {1 h each at pH 4.0 (upper stomach condition) and pH 2.0
(lower stomach condition); and 6 h at pH 7 (small intestine condition)}. γ-oryzanol
and lycopene release from microcapsules at the end of eight hours varied between 48
to 72%, and 44 to 69% respectively.
The final concentrically encapsulated lycopene and γ-oryzanol were mainly
obtained through two processes, (i) A 2 step Process : SC-CO2 extraction of lycopene
using RBO as a co-solvent where the end product is lycopene encapsulated within
RBO and subsequently encapsulated within the protein-polysaccharide wall matrix
using spray drying; and (ii) A 3 step Process : SC-CO2 extraction of lycopene using
ethanol as a co-solvent, the extracted lycopene is encapsulated within RBO using high
pressure homogenization and spray drying to encapsulate the lycopene encapsulated
within RBO into protein-polysaccharide matrix. If we compare the two processes for
its effectiveness towards encapsulation and delivery of lycopene as well as γ-oryzanol
considering the initial contents extracted and those which were delivered into the gut,
the two step process was found to be more effective compared to the three step
process. Encapsulation efficiencies of lycopene and γ-oryzanol varied between 87.6 ±
0.52% to 93.6 ± 0.47% and 94.4 ± 0.82% to 99.5 ± 0.56% respectively for the two
step process whereas the same for the three step process varied between 80.5 ± 0.74%
to 89.5 ± 0.45% and 91.8 ± 0.78% to 97.7 ± 0.60%. The delivery efficiencies for
lycopene and γ-oryzanol for the two step process varied between 44.9 ± 1.26% to 60.5
± 1.08% and 49.2 ± 0.94% to 65.2 ± 1.05% which for the three step process varied
between 39.3 ± 1.13% to 54.1 ± 1.17% and 45.4 ± 1.20% to 57.9 ± 1.24%. If we
compare the four different combinations of protein-polysaccharide wall matrices
encapsulation efficiencies of those containing JSP were significantly higher than those
containing TP. However, the delivery efficiency into the simulated gut conditions of
wall materials containing TP was found to significantly higher than th
Description
T-10270
Keywords
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