Improved collagen extraction from jellyfish (Acromitus hardenbergi) with increased physical-induced solubilization processes.

Efficiency and effectiveness of collagen extraction process contribute to huge impacts to the quality, supply and cost of the collagen produced. Jellyfish is a potential sustainable source of collagen where their applications are not limited by religious constraints and threats of transmittable diseases. The present study compared the extraction yield, physico-chemical properties and toxicology in vitro of collagens obtained by the conventional acid-assisted and pepsin-assisted extraction to an improved physical-aided extraction process. By increasing physical intervention, the production yield increased significantly compared to the conventional extraction processes (p < .05). Collagen extracted using the improved process was found to possess similar proximate and amino acids composition to those extracted using pepsin (p > .05) while retaining high molecular weight distributions and polypeptide profiles similar to those extracted using only acid. Moreover, they exhibited better appearance, instrumental colour and were found to be non-toxic in vitro and free of heavy metal contamination.

Nutritional composition and total collagen content of three commercially important edible jellyfish.

The study aimed to evaluate nutraceutical potential of three commercially significant edible jellyfish species (Acromitus hardenbergi, Rhopilema hispidum and Rhopilema esculentum). The bell and oral arms of these jellyfishes were analyzed for their proximate composition, calorific value, collagen content, amino acid profile, chemical score and elemental constituent. In general, all jellyfish possessed low calorific values (1.0-4.9 kcal/g D.W.) and negligible fat contents (0.4-1.8 g/100 g D.W.), while protein (20.0-53.9 g/100 g D.W.) and minerals (15.9-57.2g/100g D.W.) were found to be the richest components. Total collagen content of edible jellyfish varied from 122.64 to 693.92 mg/g D.W., accounting for approximately half its total protein content. The dominant amino acids in both bell and oral arms of all jellyfish studied includes glycine, glutamate, threonine, proline, aspartate and arginine, while the major elements were sodium, potassium, chlorine, magnesium, sulfur, zinc and silicon. Among the jellyfish, A. hardenbergi exhibited significantly higher total amino acids, chemical scores and collagen content (p<0.05) compared to R. hispidum and R. esculentum. Having good protein quality and low calories, edible jellyfish is an appealing source of nutritive ingredients for the development of oral formulations, nutricosmetics and functional food.

The use of Caco-2 cells as an in vitro method to study bioavailability of iron.

Iron absorption is essential for the maintenance of iron levels in the body, since excretion is poorly regulated. Dietary factors can influence iron absorption including low molecular weight substances such as ascorbic acid which has been shown to enhance iron transport across mucosal cell monolayers. Both in vivo and in vitro work may be carried out to study iron absorption. Studies in vivo have the drawback of dealing with a complex system in which it is difficult to determine the relative importance of different factors. In vitro cell culture models could overcome this difficulty but attempts to establish differentiated enterocyte cell lines in culture have not been successful. However the Caco-2 line, derived from a colon carcinoma, is able to differentiate spontaneously when grown in standard culture conditions. The differentiated cells polarized, formed microvilli and T-junctions associated with the duodenal enterocytes brush border. This cell line thus represents an appropriate model for the study of transport mechanisms related to the intestinal barrier and can be used to study the absorption of nutrients especially iron in relation to dietary intake in particular pertaining to dietary factors that may affect absorption. In this work we have therefore used differentiated Caco-2 cells grown in bicameral chambers as a intestinal cell model to study the absorption of iron from different sources and compared it with INT 407 cells. Transfer of iron across the monolayers in the apical-to-basolateral direction has been found to be greater from feric lactoferrin than from iron citrate, while very little transport occurred from Fe-transferrin. It is concluded that in this in vitro study lactoferrin but not transferrin enhances mucosal iron transport. More importanty this study has also shown that Caco-2 can be used as an in vitro method to investigate not only iron bioavailability but can be applied to other minerals as well.

The effect of different milks and milk proteins on the growth of Bifidobacterium infantis ATCC 27920 in vitro.

Bifidobacteria is a well known bacteria that is found in abundance in the intestine of infants which provides several health and nutritional benefits. Realizing the many benefits of bifidobacteria to human, this study has been conducted with the objective to determine the growth promotional effect of different types of milk and milk proteins on Bifidobacterium species. One strains of Bifiodobacterium species that is B. infantis was used to study the growth promoting effect of human milk, cow's milk, goat's milk, milk based infant formula, soy-based infant formula, lactoferrin (1 mg/ml), lactoperoxidase (1p~g/ml), lysozyme (1 mg/ml) and the mixture of these three proteins. The growth promotion assay was done using the 96-well culture plates which consists of 200 (1 Trypticase-Peptone-Yeast extract (TPY) medium, 50 4 sample and 10 1il of bacteria inoculum. Control consists of PBS instead of the samples. The assay was incubated anaerobically at 370C for 18 hours before being spread on the agar plate containing TPY medium with agar. Comparison was made between the mean count (log cfu/ml) of different types of milks, between infant formula and between milk proteins. From the results, Oneway ANOVA test at P<0.05 showed that there was significant differences in the mean counts (log cfu/ml) between the milks (P = 0.0000). A similar trend was observed in the mean count (log cfu/mI) between the infant formulas (P = 0.0 124) and also between the milk proteins (P = 0.0005). Duncan Multiple Range tests showed that there was significant differences between all the milks and control and among the milks themselves. There was however, no significant difference among the two types of infant formulas. The milk proteins also showed significant differences between the proteins and control and among themselves except for lysozyme which showed no significant differences with lactoferrin. This study showed that the growth of B. infantis could be promoted by different kinds of milks and milk proteins in vitro. Comparing the differences in growth promoting effect between samples and control indicated that human milk has the highest growth promoting effect followed by cow's milk and the mixture of the three milk prtoeins. Lysozyme showed the lowest in term of differences in percentage of growth promoting effect among all these samples. In conclusion the findings of this study supported that human milk ios the best milk choice for infant in comparison to other types of milk in promoting the growth of bifidobacteria. In additon, this tudy also found that milk protein when used in combination may show better growth promoiotive effect than when used singly.