An overview of research on plant based natural dyes in Nepal: scope and challenges

Abstract

The worldwide demand of natural dyes is of great interest due to the increased public awareness about the atmospheric and environmental pollution caused by the commercially available synthetic dyes. Nepal being wealthy in flora, would be fine research laboratory land for the plant based natural dyes. Among most of the natural dyes, plant-based dyes/pigments have wide range of applications in fabric, food, drug coloring, therapeutic values and also in solar cells in presence of different mordants. The use of mordant is inevitable during natural dyeing process in order to improve the fastness properties on fabrics, foods and drugs by forming a co-ordination complex with dye. In this article, a short overview of plant based natural dyes extraction applications and their scope and limitations will be discussed with special reference to Nepal. In the present review, the green methods of dye extraction, and dyeing technologies will be discussed, and the research fields based on natural dyes will be explored. Some of the natural dyes has also shown the antimicrobial, antioxidant, antifungal properties and hence are also discussed with biomedical applications.

Evaluating Budgeted and Actual Sales Performance in the Dairy Industry: A Case Study of the Dairy Development Corporation (Ddc) in Nepal

“…However, the dairy sector in Nepal faces challenges that hinder its growth and sustainability. One of the key challenges is the interference of political influences and the lack of autonomy and accountability within public enterprises such as the DDC (Bhandari et al, 2017). This interference often results in inefficiencies and suboptimal resource allocation, negatively impacting the financial stability and performance of the dairy sector (Thapa et al, 2021).…”

Environmental friendly application of ultrasonic rays for extraction of natural colorant from Harmal (P. harmala) for dyeing of bio-mordanted silk

“…In place of such chemicals, now plant-based mordants are used which not only can give the variety of shades but also have ability to valorize the dyeing process by giving good to excellent fastness ratings. 22,23 For getting effective isolation of functional and potent bio-molecules (natural colorant), new modern methods such as microwave, 24,25 ultrasonic, 26,27 gamma rays, 28 Ultraviolet, 29 plasma, 30 supercritical fluid, 31 etc., are now taking considerable attention due to their cost, time, and energy effective nature. Ultrasonic rays (U.S. rays) are considered as uniform and leveled heating sources with excellent energy transfer mechanism into the isolation system.…”

Eco-friendly approach towards isolation of colorant from Esfand for bio-mordanted silk dyeing

“…The colorants cover a full spectrum of colors and have excellent compatibility with the fabric and the environment. Mostly, the plants which bear natural dyes are part of great ayurvedic systems, such as Chinese, Greek, and Indian medicine systems (Bhandari et al 2020;Mansour and Yusuf 2018;Loum et al 2021). In this study, Esfand seeds (Peganum harmala) have been selected as a dye-yielding source.…”