Effect of ph on the stability of red beet extract (Beta vulgaris l.) microcapsules produced by spray drying or freeze drying

Abstract Red beets is rich in phenolic acids and has high antioxidant capacity, and can be used to produce a natural dye. This study evaluated the effect of pH (3 to 6) on the stability of red beet extract microcapsules, dried by freeze drying and spray drying and stored at room temperature. The microcapsules were produced using a combination of maltodextrin and xanthan gum as encapsulating agents and stored for 7 days. For all evaluated microcapsules, a degradation of betanin was observed, however, that degradation was independent of pH, with the exception of the sample with maltodextrin and dried by spray drying. The freeze dried products showed lower degradation constants and higher half-life (t1/2) when comparing with the spray dried samples. The microcapsules containing maltodextrin and xanthan gum, dried by spray drying, showed the highest change in the content of phenolic compounds after storage for 7 days. The color parameters showed a reduction for a*, and increase in b* and L*, for all samples during the storage time. In general, the microcapsules produced using maltodextrin and xanthan gum, and dried by freeze dryer, showed higher stability in terms of betanin content, phenolic compounds and color parameters during storage at different pHs.

Harnessing Natural Colorants for Sustainable Textile Dyeing an Eco-Friendly Approach Using Sweet Cane (Saccharum Bengalense Retz.) Inflorescence

ABSTRACT The excessive industrial use of dye producing plants has threatened the existence of these species and biodiversity. Exploration of abundantly available natural dye sources not only provide industrial benefits but also share the load of dye yielding plants. In the present study we used the inflorescence of munj sweet cane (Saccharum bengalense Retz.) to extract natural colorant for textile industry. This easily available plant is cheap source of natural colorants and good alternative of synthetic dyes. The munj sweet cane inflorescence extract and fabric was treated with microwave radiations. The dyeing aspects like temperature, time, fabrics to extract ratio, salt type and salt concentrations were optimized. Pre-and post mordanting was carried out and optimized using copper, iron, moringa and turmeric. All the samples were analyzed by spectra flash D65 10 Deg to determine the color strength (%) value. Results proved inflorescence extract of munj sweet cane (RS, two minutes) using aqueous media as a good source of natural dye. Three grams of sodium chloride as exhaustion agent was observed to be the best while 70 0C temperatures gave best colour strength. Among chemical mordants, iron proved to be good one for producing varying shades and better colour strength. Bio mordanting with turmeric was proved to be more beneficial for getting best color strength and new shades.

Immobilization technique of natural dyes, as a novel method to preserve industrially important E. coli and Bacillus species.

Immobilization is a method used for the preservation of enzymes as this method provides enhanced resistance to the changes in certain environmental conditions like pH/temperature. The advantage of immobilization (IMB) of live bacterial cells is especially high due to their role in environmental monitoring due to their low cost, easy handling and high sensitivity to the environment. Through our project we tried to show that this method of IMB is effective in the preservation of microorganisms. We used natural dyes during the course of our project which were extracted from grinding of fruits and vegetables such as pomegranate, beetroot and carrot. We used Sodium Alginate beads so that there were a good number of beads formed that helped for the proper entrapment of microorganisms E. coli and bacillus for future use. Natural dyes were chosen over synthetic dyes due to their environmental friendliness, cost effectiveness and less complexity. To confirm if the method had been effective, we prepared a growth curve to check the growth of the microorganism and found out that this method could be used to store the microbes for a month’s duration.

Extraction of Indigo from Some Isatis species and Dyeing Standardization Using Low-technology Methods

Fresh leaves of four Isatis species culture form of I. tinctoria L and wild forms of I. buschiana Schischkin, I. candolleana Boiss. (endemic) and I. tinctoria L. subsp. corymbosa. (Boiss.) were used for indigo production. Dyes were extracted by fermentation and hot water application. The extracted dyes were optimized with different pH and reducing agents. Results showed that the dye from hot water application produced the desired dying quality at pH 11. Reducing agent concentrations had no significant effect on color quality. Dark blue and blue colors were obtained from I. tinctoria and I. candolleana extracts although I. tinctoria subsp. corymbosa and I. buschiana produced mostly yellow-gray colors. Light, dry and wet rubbing fastness values varied between 3 and 3/4 while washing fastness was between 2 and 4/5. The highest indigo amounts were determined spectrophotometrically as 4.19 mg/g and 2.53 mg/g in I. tinctoria and I. candolleana, respectively. Results also showed that harvesting season was important for indigo production and the highest indigo amount was observed in mid-June.

An efficient in vitro regeneration protocol for a natural dye yielding plant, Strobilanthes flaccidifolious Nees., from nodal explants.

Adventitious shoot buds formation from axillary buds of nodal segments of S. flaccidifolious was achieved on MS medium containing sucrose (3%, w/v), and α-naphthalene acetic acid (NAA; 3 µM) and benzyl adenine (3 µM) in combination. The nodal segments were primed on ‘Growtak Sieve’ for 48 h on MS medium containing sucrose (2%), polyvinyl pyrollidone (200 mgL-1) as antioxidant. About 80% of primed nodal segments responded positively and formed ~12 adventitious shoot buds per explants from explants collected during October-November months of every year. The shoot buds converted into plantlets on MS medium containing sucrose (3%) and kinetin (3 µM) where ~7 micro shoots developed per subculture after 8 weeks of culture. The regenerated micro shoots induced average 14 roots/ plant on medium containing NAA (3 µM). The regenerates were hardened for 6-7 weeks on medium with ½MS salt solution and sucrose (2%) under normal laboratory condition before transferring to potting mix. About 70% transplants survived after two months of transfer.

Anti-microbial activity of turmeric natural dye against different bacterial strains.

Curcumin, a yellow pigment present in the Indian spice turmeric (associated with curry powder), has been linked with suppression of inflammation; angiogenesis; tumorigenesis; diabetes; diseases of the cardiovascular, pulmonary, and neurological systems, of skin, and of liver; loss of bone and muscle; depression; chronic fatigue; and neuropathic pain. The utility of curcumin is limited by its color, lack of water solubility, and relatively low in vivo bioavailability. Because of the multiple therapeutic activities attributed to curcumin, there is an intense search for the ‘‘super curcumin’’. In the present study anti microbial activity of turmeric natural dye against different bacterial strains. In the present study in vitro, test confirmed the antimicrobial activity of turmeric extract against ten different bacterial strains. The antibacterial activity was measured by agar well diffusion method. The natural dye showed antibacterial activity against all the test bacterial isolates. Turmeric natural dye showed good inhibitory activity against E.coli and Vibrio cholera with a zone of inhibition 7mm to 15mm and 10mm to 15mm respectively. As turmeric powders are used to color natural fibers from which consumer products are manufactured. The incorporation of turmeric dye with natural fiber will help to produce value added handicrafts.