Research Papers
Welcome to our collection of research papers. Here you can explore our latest findings and insights in the field of natural pigments and their stability in food. Our team is dedicated to sharing valuable knowledge and contributing to the scientific community.
ChromaQuest project is expected to deliver 3 publications in Q1 and Q2 scientific journals, as well as 3 conference proceedings.
This section will be updated as the project progresses.
Optimised extraction and encapsulation-based stabilisation of chlorophyll from conifer needles for use as a food colourant
PUBLISHED
Conifer needles from logging residues represent an abundant but underused source of chlorophyll for natural food colourants. This study evaluated the extraction, stabilisation, and food application of chlorophyll from Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) needles. Chlorophyll recovery was compared across two species, fresh and dried needles, several solvents, and three extraction methods: ultrasound-assisted extraction (UAE), maceration, and Soxhlet extraction. Fresh spruce needles yielded the highest chlorophyll-a content (approximately 0.31 g per 100 g dry weight, versus 0.24 g for pine), and fresh material consistently outperformed dried material. UAE achieved yields comparable to the conventional methods in only 30 minutes, with lower energy use, and acetone was the most effective solvent. Optimisation by response surface methodology identified the biomass-to-solvent ratio as the dominant factor governing pigment recovery. To assess stability in a food matrix, the extract was encapsulated in maltodextrin and inulin and incorporated into yoghurt. Storage temperature was the decisive factor in colour retention: refrigeration at 4 °C preserved colour over six days, whereas storage at 21 °C caused pronounced colour loss through conversion of chlorophyll to pheophytin. The two carriers performed similarly, and an inclusion rate of approximately 3% provided optimal coloration. Overall, the results establish UAE with acetone as an efficient extraction route and demonstrate a viable path for converting a low-value forestry side-stream into a stable, food-compatible natural pigment within a circular economy framework.
The multifunctionality of plant pigments: roles, recovery from by-products and stability challenges
PUBLISHED
The growing demand for natural pigments in food, cosmetic, and pharmaceutical applications is driven by increasing concerns over the safety, sustainability, and environmental impact of synthetic dyes. Natural pigments derived from plants, algae, and microbial sources offer functional and health-promoting properties but are often limited by intrinsic instability and challenges related to scalable and sustainable production. This review provides a comprehensive overview of major plant pigment groups - anthocyanins, carotenoids, chlorophylls, and betalains, with particular emphasis on their biological roles, chromatic properties, and stability characteristics focusing on the valorisation of food processing by-products and agro-industrial wastes as abundant and low-cost pigment sources within a circular bioeconomy framework. Recent advances in green and non-thermal extraction technologies, including ultrasound-, microwave-, enzyme-assisted extraction, pulsed electric fields, supercritical
fluid extraction, and natural deep eutectic solvents, are critically discussed in terms of efficiency, sustainability, and applicability. In addition, current stabilisation strategies, such as microencapsulation, nanoemulsions, and copigmentation, are reviewed as complementary approaches to enhance pigment functionality and application potential. Regulatory inconsistencies and consumer acceptance further shape innovation uptake. Bridging laboratory advances with industrial practice requires pilot-scale validation, techno-economic assessment, and harmonised safety standards.
Effect of drying temperature on berry press residue anthocyanin stability and profile
PUBLISHED
This research investigates how various drying techniques and temperatures impact the preservation of anthocyanins and polyphenols within berry press residues. By comparing ten different species, the study determines that freeze drying offers the best protection for these health-promoting compounds, followed closely by vacuum drying at moderate temperatures. Scientists discovered a significant degradation threshold above 75 °C, where extreme heat and oxygen exposure cause rapid loss of antioxidants across all varieties. Furthermore, the analysis highlights that molecular structure dictates stability, as rutinoside-type anthocyanins withstand thermal stress much better than other forms. These findings provide a framework for the industrial upcycling of berry waste into high-value functional food ingredients. Ultimately, optimizing these processes supports environmental sustainability by transforming juice production by-products into shelf-stable, nutrient-rich resources.