• KSBB Journal
• /
• v.29 no.6
• /
• pp.437-442
• /
• 2014

In vitro biological activities of Aloe vera gel and skin extracts were evaluated. Total polyphenol contents of Aloe vera skin were measured 41.12 mg/g. DPPH radical scavenging activity of Aloe vera skin-70% EtOH extract, Aloe vera skin-water extract, Aloe vera gel-70% EtOH extract and Aloe vera gel-water extract were 55%, 38%, 11% and 10%, respectively. In addition, 70% EtOH extract and water extract were compared with respect to SOD-like antioxidant activity of Aloe vera-70% EtOH extract has higher activity than Aloe vera water extract. Tyrosinase inhibition rate of Aloe vera gel extract was higher than Aloe vera skin extract. Alcohol dehydrogenase (ADH) and Acetaldehyde dehydrogenase (ALDH) relative percentage activity of Aloe vera gel extract were 126% and 216%, respectively. It was suggested that Aloe vera gel and skin extracts could be used as a functional biomaterial for functional food and cosmetics.

• KSBB Journal
• /
• v.28 no.6
• /
• pp.356-365
• /
• 2013

The novel Aloe gels were prepared with dewatering and impregnation by soaking (DIS) processing of Aloe vera leaf slice at four different temperatures (25, 35, 45 and $55^{\circ}C$), using dehydration solution of 40% (w/v) polyethylene glycol (PEG4000). The PEG-impregnation to Aloe vera leaf slice during DIS was observed depending on immersion temperature, and the PEG-impregnated Aloe vera gel (PEG-i-AVG) obtained was characterized using $^1H$ NMR, FT-IR, GPC, XRD and TGA. The PEG-i-AVG had the higher levels of Aloe bioactives (glucomannan and O-acetyl contents) and better quality indices by $^1H$ NMR and FT-IR spectroscopy than those of native Aloe gel. Also, the obtained Aloe gel maintained the bimodal patterns in higher molecular weight region by GPC indicating no degradation of polysaccharide from native Aloe gel. The result observed by SEM confirmed a surface modification by forming the porous structure, and TGA result exhibited better thermal stability than that of native Aloe gel. XRD result revealed that the crystalline structure in Aloe gel was led by incorporation of PEG. Significant decrease of %insolubility and high enhancement of water solubility index were observed, respectively, and highly ordered conformation such as a helix structure was also indicated by Congo red reaction. We concluded that the modification effect for enhancing function of native Aloe gel was successfully obtained by DIS process using PEG as a dehydrating agent. These results suggested that this DIS process had a high potential for developing a new minimally processed product from Aloe vera leaf.

• Korean Journal of Food Science and Technology
• /
• v.41 no.1
• /
• pp.32-36
• /
• 2009

The physical properties of freeze-dried Aloe vera gel powders were examined according to the influence of the concentration degrees of the gel solutions as raw materials during freeze-drying. As a pre-treatment prior to freeze-drying, the gel solutions were vacuum-concentrated at three concentration levels (g water/g solids): high (H), 76; medium (M), 119; and low (L), 159. The water contents of the three powder samples were almost the same. For their viscosity measurements, non-Newtonian fluid behavior with shear thinning was observed in samples H and M, whereas Newtonian liquid behavior was found in sample L. In electrical conductivity measurements, sample H showed the highest conductivity upon dissolving the powder in water. For their water sorption isotherms, sample H was analyzed to have the least amount of bound water. Finally, it was determined that the degree of concentration caused only slight differences in the physical properties of freeze-dried Aloe gel powders.

• KSBB Journal
• /
• v.23 no.2
• /
• pp.169-176
• /
• 2008

The concentration of fresh gel from Aloe vera L. by using ulfrafiltration (UF) process was investigated and analyzed. The two membranes (organic and ceramic) with different molecular weight cut-off (MWCO) and modules (flat sheet and tubular) was used. Under optimum operation conditions, ceramic (zirconium dioxide) tubular membrane with MWCO of 50 kDa resulted in higher flux, less fouling, more turbid, higher total solid, higher polysaccharide and less aloin content. Optimum operation conditions were transmembrane pressure of 1.0 bar, feed velocity of 240 L/hr and temperature of $23^{\circ}C$. Volume concentration factor of aloe gel was 3.13 at permeate flux of $51.1\;L/m^2{\cdot}hr$ after processing time of 1.66 hr. Aloin in fresh aloe gel by UF process was effectively removed as permeate and bioactive polysaccharide content was 2.1 times higher than that of fresh aloe gel. These results allowed a very good level of concentration degree and polysaccharide content. Thus, ultrafiltration process of this study was suitable for the concentration of fresh aloe gel though the aloe concentrate showed both the viscosity decrease and partially separation of liquid layer during storage at $4^{\circ}C$.

• The Korean Journal of Food And Nutrition
• /
• v.13 no.2
• /
• pp.146-151
• /
• 2000

To evaluate anticaries and antiinflammation of Aloe vera peel, antimicrobial substances were extracted from Aloe vera peel and identified. The antimicrobial active substances of water extract were successfully purified with solvent fractionation, silica gel column chromatography, preparative thin layer chromatography and UV spectrophotometer. Two purified active substances were identified as aloe-emodin and barbaloin by Mass Spectrometer, 1H-NMR and FT-IR.

• Food Engineering Progress
• /
• v.13 no.4
• /
• pp.251-261
• /
• 2009

In vitro physiological functions such as jack bean (Canavalia ensiformis) urease inhibitory activity and retarding effect of glucose/bile acid of Aloe vera gel concentrated by the optimized DIS (Dewatering Impregnation & Soaking) process conditions were examined. Urease inhibitory activity of DIS aloes ranged from 84.6 to 94.4%, which was similar to or higher than 86.3% of fresh aloe. Also, urease inhibitory activity of DIS aloes was maintained at initial levels after heat treatment (90$^{\circ}C$, 10 min.) and drying treatment (freeze or hot air drying). Urease inhibition pattern from Lineweaver-Burk plot indicated general non-competitive inhibition, and inhibition constants ($K_{IE}$ and $K_{IES}$) of DIS aloes were 41-149 and 87-163 $\mu$L/mL, respectively. DIS(glucose) and DIS(polyethylene glycol) exhibited the highest retarding effect of glucose and bile acid. Their retarding effects were about 1.6 and 1.8 folds higher than that of fresh aloe after 0.5 and 1 hr of the dialysis, respectively. Conclusively, the above in vitro physiological functions of Aloe vera gel concentrated by DIS process suggested that aloe products treated with DIS would have the potential benefits for protection against Helicobacter pylori and reduction of blood glucose and cholesterol levels.

• Korean Journal of Food Science and Technology
• /
• v.44 no.5
• /
• pp.643-647
• /
• 2012

The antioxidant capacity of aloe vera gel (AG), aloe vera exudates (AE), and a low molecular filtrate of aloe vera gel (ALMF) prepared from aloe vera grown on Jeju Island, Korea was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS), and oxygen radical absorbance capacity (ORAC) assays, and total phenolic content (TPC), and total flavonoid content (TFC) were determined. The phenolic compounds in aloe samples were analyzed. Antioxidant capacities in oil-in-water emulsions following riboflavin photosensitization were analyzed using lipid hydroperoxide. AE had significantly higher antioxidant capacity than that of the other samples based on the DPPH, ABTS, and ORAC assays (p<0.05). Lipid hydroperoxide values of 5 mg/mL for AG, AE, and ALMF were 521.78, 272.32, and 699.89 mmol/kg oil, respectively, whereas that of samples without aloe vera was 893.07 mmol/kg oil over 48 h. AE had higher TPC and TFC values. Aloesin and aloin were found in AE, whereas those compounds were only found in trace amounts in AG and ALMF.

• Korean Journal of Pharmacognosy
• /
• v.47 no.2
• /
• pp.103-109
• /
• 2016

Aloe vera L.(Aloe barbadensis Miller) has been used for many centuries for various medical, cosmetic and neutraceutical purposes. The gel of A. vera was reported to exert numerous biological activities including wound healing, immunomodulatory, anti-cancer, anti-inflammatory, anti-bacterial, anti-viral, anti-diabetic, and anti-psoriasis activities. Acemannan, found predominantly in the inner leaf gel of A. vera, has been identified as the main active ingredient exerting diverse biological activities. In this review, we summarized the recent findings on the immunomodulatory activities of acemannan. Studies that used purified acemannan demonstrate that acemannan exerts immune-stimulating, anti-cancer, anti-viral, and hematopoiesis-increasing activities. In addition, it is being clear that most of these activities of acemannan are mediated primarily by activating professional antigen presenting cells such as macrophages and dendritic cells.

• KSBB Journal
• /
• v.28 no.5
• /
• pp.319-326
• /
• 2013

This study was carried out to investigate the in vitro and in vivo moisturizing properties and percutaneous absorption of PEG-impregnated Aloe vera gel. The PEG-i-Aloe gel was obtained from dewatering and impregnation by soaking (DIS) of Aloe vera leaf slice. The moisturizing property of the obtained sample was evaluated by moisture determination using gravimetric method in desiccator under different RH% and by water sorption-desorption test on human skin. The transdermal penetration characteristics of PEG-i-Aloe gel was investigated by Franz diffusion cell in vitro transdermal absorption method. PEG-i-Aloe gel had high moisture retention ability and could significantly lead the enhancing skin hydration status as well as reducing the skin water loss due to the film formation as a skin barrier. The skin penetration rate of PEGi- Aloe gel at steady state was 9.76 ${\mu}g/(h{\cdot}cm^2)$ and the quantity of the transdermal absorption was 144 ${\mu}g/cm^2$ in 9 hr. The penetration mechanism was well fitted with Higuchi model ($R^2$ = 0.974-0.994). The results show that PEG-i-Aloe gel has the significant moisturizing effect and strong penetration of the animal skin. It could be used as the moisturizing additive in cosmetic skin products.

• Food Engineering Progress
• /
• v.13 no.3
• /
• pp.216-220
• /
• 2009

The several functional properties of freeze-dried powder of Aloe vera gel was examined as influenced by pre-concentration degrees of the gel solution. As a pre-treatment prior to freeze drying, the gel solution was vacuum-concentrated by three levels (unit: g-water/g-solids) - high (H), 76; medium (M), 119; low (L), 159. In FT-IR spectra, the sample H showed the highest absorbance in the range of 1600-1550 $cm^{-1}$ and 1450-1400 $cm^{-1}$, which corresponded to level of the acetyl group in glucomannan. The sample H of freeze-dried powder was the highest in polysaccharide content, jack bean urease inhibition rate, and FAC (fat adsorption capacity). It could be inferred that the sample H had an effect on Helicobacter pylori inhibition and fat adsorption suppression according to urease inhibition rate and FAC, respectively.