Influence of Aloe Gel Enrichment on the Physicochemical, Textural and Sensory Characteristics of Dahi

Aloe gel, derived from Aloe vera plant is well known for its nutraceutical potential, It is available commercially as a juice with poor sensory quality. The therapeutic benefits of Aloe gel could be extended to food products concomitantly improving its acceptability. Dahi/curd is an Asian fermented dairy product that enjoys tremendous mass appeal. The objective of the present study was to formulate dahi enriched with Aloe gel （AG） as a functional ingredient and to study its effect on the quality of dahi. Plain dahi was prepared by addition of 2.5% skimmed milk powder （SMP） and suitable starter to milk. For the preparation of AG enriched dahi, SMP was replaced by AG at different levels （0.1-0.25%）. The products were evaluated for moisture, pH, titrable acidity （TA）, whey syneresis （WS）, total solid content （TS）, water holding capacity （WHC）, total yield （TY）, whiteness index （WI）, and viscosity. Microbial analysis and sensory evaluation were also carried out. Enrichment of dahi with AG was found to improve its quality characteristics by causing a significant reduction in WS and an increase in TA, TS, WHC, TY, WI and viscosity. AG dahi recorded good sensory acceptability. Storage study also indicated AG dahi to perform better in terms of the various parameters studied. The present investigation suggests the feasibility of adding Aloe gel powder as a functional ingredient to dahi to enhance product quality as well as its nutritional and therapeutic potency. It could be commercially exploited as a novel product.

A Simple Bio-preservation Technique to Increase Shelf Life of Ampalavi Mango Fruits Using Aloe vera Gel

Aloe vera is being identified as a potential medicinal plant for its application in industries as well as traditional usage. The gel obtained from the leaves of A. vera has numerous properties. In this study, using the gel to extend the shelf life of Ampalavi mango fruits was studied. Even sized, uniform coloured, matured Ampalavi cultivar mango fruits were surface cleaned and coated with 33%, 66% and 100% gel, respectively. Results revealed that the ripening was delayed due to the coating. The total soluble solid （TSS）, pH and weight loss were high in uncoated fruits. The mean pH of the pulp from fruits kept as control was 4.94 at 4 d fruit preservation period （FPP） and was slightly increased to 5.43 within 12 d FPP, whereas the minimal pH （4.69 at 4 d FPP and 5.03 at 9 d FPP） was noticed in 100% gel coated fruits. The TSS （brix） was significantly in higher levels （13.67°Bx within 4 d FPP and 20.77°Bx within 12 d FPP） in control fruits, whereas the minimum TSS value was 9.27°Bx and 18.03° Bx within 4 d and 12 d FPP, respectively, recorded from the 100% gel coated fruits in storage. The weight loss percentage （WLP） was significantly （P 〈 0.05） higher in control fruits （8.46%）, whereas the lower WLP （1.13%） was found in 100% gel coated fruits after 12 d of storage. This low-scale gel coating technique prolonged the fruits shelf life by delaying the fruit ripening. This effect has to be further investigated to commercialize the natural product for large scale ready-made application.

Regeneration of Cytologically Stable Plants Through Dedifferentiation, Redifferentiation, and Artificial Seeds in Spathoglottis plicata Blume.(Orchidaceae)

Spathoglottis plicata Blume. is a horticulturally important vulnerable ground orchid with beautiful flowers blooming round the year. Highfrequency protocorm-like body(PLB) formation was established via callus culture from vegetative tissues of in vitro germinated seedlings of S.plicata. Media containing MS salts and Gamborg's B5 vitamins supplemented with 1.0 mg·L^(-1) 2,4-dichlorophenoxyacetic acid(2,4-D), 3.0 mg·L^(-1) α-naphthaleneacetic acid(NAA), 1.0 mg·L^(-1) kinetin(KIN), and 10%(v/v) ‘Aloe vera gel'(Av G) were effective in fragile calli induction. A maximum of(22.3 ± 0.52) PLBs were induced from about 250 mg callus within 45–55 days in the presence of 2.0 mg·L^(-1) NAA and 3.0 mg·L^(-1) 6-benzylaminopurine(BAP). Briefly, 3.0% sodium alginate was found to be most suitable for the formation of an appropriate shape and good germination rates(86.7%)of artificial seeds. Out of three different temperatures(4, 15, and 24 °C), the best result was achieved at 4 °C with 66.7% germinability even after90 days of storage. Plantlets were acclimatized with 86.6% survival rate and 76.3% of these plants produced flowers within 12–15 months of field transfer. Chromosomal studies revealed cytological stability of all regenerants containing 2 n = 40 chromosomes as in the parental plants.The present protocol can be applied reliably for the purposes of large-scale commercial propagation and short-term conservation of this orchid.

不同来源的芦荟对酪氨酸酶的抑制作用(英文)

In this study, lyophilized and methanolic extracts of aloe gel from different germplasms were evaluated for their potential to inhibit mushroom tyrosinase activity. The results showed potent inhibitory effect of Aloe vera gel extracts on L-dihydroxyphenylalanine(L-DOPA) oxidation catalyzed by tyrosinase in a dose-dependent manner. Significant differences in % inhibition of tyrosinase among the extraction methods and the germplasms were observed. The relative performance of the germplasms was evaluated with the help of posthoc multicomparison test. The methanolic extract was more effective than the lyophilized crude gel in all the germplasms. The inhibitory effect of the lyophilized gel and methanolic extract tested from five germplasms followed the order: RM > TN > S24 > OR > RJN. The germplasm RM showed the highest tyrosinase inhibition, and the maximum % inhibition noted was 26.04% and 41.18%, respectively for the lyophilized and methanolic extracts at 6 mg·mL–1concentration. Lineweaver-Burk plots of the different concentrations of L-DOPA in the absence and presence of lyophilized gel extract showed competitive inhibition of mushroom tyrosinase in all the germplasms. This study suggests that the germplasm RM could potentially be used for the isolation and identification of the effective tyrosinase inhibitory component, and ascertains the critical role of selecting the best source of germplasm for natural product isolation and characterization.