Health and environmental concerns associated with synthetic ingredients in cosmetics have driven consumer demand for natural and eco-friendly alternatives [1]. In this study, a combination of microbial red colourant and SCO2 extracted hemp seed oil was utilized to formulate a lip salve, aiming to maximize consumer benefits. Microbial pigments provide subtle hues with versatile presence by virtue of being industrially scalable, therapeutically active, environmentally non-toxic, and biotechnologically adaptable. Monascus, a well-known fungus for transforming normal rice to red koji rice, impart yellow to maroon shades while exhibiting in-built sun protective, antioxidant, antimicrobial and anti-inflammatory properties. Ankaflavin, a patented pigment from Monascus is being utilized as a natural tanning agents in several formulations [8, 9]. Red colourant extracted through endophytic fungus T. assiutensis CPEF04 exhibited anti-bacterial, antioxidant and anticancer activities while being non-toxic to Human Embryonic Kidney 293 T cells expanding its use as a cosmeceutical [5].
Oils obtained through green SCO2 extraction exhibit enhanced functional activity due to the optimal retention of bioactive compounds, making them highly suitable for eco-friendly cosmetic products. The current investigation yielded 37% of hemp seed oil and GC-MS analysis revealed a high concentration of beneficial mono- and polyunsaturated fatty acids, including linoleic, linolenic, oleic, and palmitoleic acids (Fig. 2). Prominently, 70% of hemp oil comprises essential fatty acids from the ω-3 and ω-6 families, which the human body cannot synthesize. These fatty acids, with a unique 3:1 ω-6 to ω-3 ratio (2.47:1 in this study), contribute to heart health, cell growth, immune support, and toddler development. Hemp oil also exhibits antioxidant, antibacterial, anti-inflammatory, and antifungal properties, enhancing its value as a natural moisturizer and therapeutic agent for cardiovascular health, cholesterol normalization, digestion, and stress reduction [2].
A lip salve hydrates, protects against environmental stressors, and nourishes the lips, promoting softness and preventing chapping. The lip salve formulations in the current study exhibited varying textures and consistencies, as summarized in Table 1. Shea butter enhanced moisturizing, while hemp oil provided nourishment and served as a viscous base. Aloe vera juice facilitated uniform ingredient incorporation by bridging immiscible oil and water phases. Beeswax used to enhance stability, acted as a solidifying agent but reduced pigment vibrancy at higher concentrations. The standardized F7T formulation achieved a butter: oil: beeswax: pigment ratio of 1:1:0.25:1 (for dark shades). An unpigmented control lip salve (butter: oil: beeswax: pigment ratio of 1:1:0.25:0) was compared with the pigmented F7T lip salve to evaluate physicochemical, stability, and sensory properties (Tables 2 and 3; Fig. 3). The control exhibited a hardness value of 1.6 ± 0.2 kg, typical of butter-based formulations, while F7T showed reduced hardness, indicating the softening effect of the microbial pigment, as confirmed by sensory analysis. F7T demonstrated a higher SPF, suggesting UV-protective properties of the pigment, and a slightly acidic pH due to anthraquinones acting as acid dyes. CIEl*a*b* analysis revealed that F7T's shade closely matched Pantone 2449 CP (#482626). Physicochemical properties such as pH, colour and weight remained stable for all formulations at various temperatures, however, spreadability and texture of control lip salve was modified at cold temperature. This showed that the pigmented F7T lip salve remains stable at low temperatures, likely due to the softening effect of the microbial pigment, which reduces excessive solidification of butters and beeswax. These findings highlight the potential of employed microbial colourant in enhancing the functional and aesthetic attributes of lip salves.
Table 1
Different ratios of base formulations and their sensory characteristics
Base | F1T | F2T | F3T | F4T | F5T | F6T | F7T |
|---|
Butter | 1.25 g | 0.6 g | 0.5 g | 1.25 g | 1.55 g | 1.4 g | 1 g |
Oil | 1 mL | 1 mL | 1 mL | 1 mL | 1 mL | 1.3 mL | 1 mL |
Beeswax | 0.25 g | 0.35 g | - | 0.5 g | 0.3 g | 0.5 g | 0.2 g |
Pigment | 2 g | 1.5 g | 0.2 g | 0.5 g | 0.1 g | 0.2 g | 1 g |
Ratio (butter: oil: beeswax: pigment) | 1.25: 1: 0.25: 2 | 0.6: 1: 0.35: 1.5 | 0.5: 1: 0: 0.2 | 1.25: 1: 0.5: 0.5 | 1.55: 1: 0.3: 0.1 | 1.4: 1: 0.5: 0.2 | 1: 1: 0.2: 1 |
Sensory observation | Good spreadability, burgundy pigment | Less chunky, spreads easily, orange pigment | Needs more butter, too oily, light orange pigment | Average consistency, very light orange pigment | Average consistency, light orange pigment | Too thick to spread, orange pigment | Best spreadability, burgundy pigment |
Table 2
Physicochemical properties of unpigmented control and selected pigmented F7T lip salves
Formulation | Ratio (butter: oil: beeswax: pigment) | Sensory observation | Hardness (kg) | SPF | pH | Colour Intensity |
|---|
Control | 1: 1: 0.25: 0 | Comparatively less smooth, good spreadability, colourless | 1.6 ± 0.2 (butter-based salves) | 21 ± 2.7 | 5 ± 0.3 | L*: 65.96 a*: -4.95 b*: 23.55 |
F7T | 1: 1: 0.25: 1 | Burgundy colour, smoother texture, good spreadability | 1.3 ± 0.8 (increased smoothness) | 34 ± 1.3 | 4.6 ± 0.6 | L*: 17.95 a*: 15.44 b*: 7.17 |
Table 3
Stability and sensory evaluation of unpigmented control and pigmented F7T lip salves
Formulation | Temperature (° Celsius) | Weight (in grams) | pH | Colour | Spreadability | Texture | Sensory observation |
|---|
Control | 4 | Variation of ± 0.3 | Variation of ± 0.5 | Normal | Modified | Modified | Comparatively harder to apply |
37 | Variation of ± 0.5 | Variation of ± 0.2 | Normal | Normal | Normal | Softest application |
45 | Variation of ± 0.6 | Variation of ± 0.5 | Normal | Normal | Normal | Smooth to apply |
F7T | 4 | Variation of ± 0.4 | Variation of ± 0.3 | Normal | Normal | Normal | No variation in application |
37 | Variation of ± 0.4 | Variation of ± 0.4 | Normal | Normal | Normal | Softest application |
45 | Variation of ± 0.5 | Variation of ± 0.6 | Normal | Normal | Normal | Smooth to apply |
The sensory profile of the pigmented lip salve was evaluated based on qualitative attributes, including aroma, taste, appearance, application, and after-effects (Fig. 3). Similar ratings for taste, application, and after-effects in both the control and F7T formulations indicate that the pigment does not alter the fundamental properties of the lip salve. However, violin graph analysis shows that a majority of panellists rated F7T higher (8 or 9) for application and after-effects compared to the control. In contrast, the control formulation scored better in taste, highlighting a potential area for improvement in F7T formulation. For appearance and aroma, F7T was favoured, possibly due to its vibrant shade and the human brain's tendency to associate bright colours with pleasant scents. Overall, the sensory evaluation highlights the promising attributes of the F7T formulation, particularly in appearance, aroma, application, and after-effects, while identifying taste as a key area for further optimization to enhance consumer acceptance.
Earlier imagined as a dystopian thought, circular biorefinery approaches are slowly seeping in our day to day lives in diverse forms [3]. Microbial colorants, as the one used in this study, are vegan, cruelty-free, non-toxic, therapeutically active, and eco-friendly alternatives to the harmful synthetic dyes. Furthermore, their production through biotechnological routes can contribute to the bioeconomy while shifting the skillsets of dye workers from chemical synthesis to biological synthesis, thereby creating non-toxic working conditions [9]. Their scalable production can ensure widespread availability, benefiting low-resource regions where other natural dyes may be inaccessible, unfeasible or unaffordable. Employing microbial colourants in cosmetics can attain the three pillars of sustainability: environmental, economic and social. Despite their vast potential, only 1% of microbial flora has been explored for pigment extraction. This calls for research on the rest of microbial strains and enhancing pigment production via genetic engineering, fermentation advancements, and cost-effective substrates. Addressing safety concerns and identifying pharmacological mechanisms will further support commercialization [10].
SCO2 extraction is an advantageous technique in cosmetics sector in terms of eco-friendliness, high bio-functional activity and purity [2]. Several organizations promote the cultivation and commercial farming of commercially important crops among economically disadvantaged farmers, aiming to mitigate soil erosion and support sustainable rural livelihoods. However, future research should focus on decreasing the capital expenditure required to establish an industrial scale facility near the cultivation areas. Furthermore, lifecycle assessments should be conducted to quantify environmental benefits, ensuring transparency in such sustainable practices. The scientific community should focus on biotechnological advancements leveraging waste recycling, circularity models, and green chemistry principles to minimize environmental impact while effectively communicating updates to the public. Government and industrial stakeholders must foster academia-industry collaborations to develop standards, offer incentives for low-carbon and bio-based product development, and promote outreach programs and marketing strategies to expand consumer awareness [10]. Consumers, in turn, should adopt a mindset of conscious consumerism, embracing sustainable alternatives for collective societal benefit. Integrating sustainable practices, such as microbial pigments and supercritical extraction, into cosmetics production not only addresses environmental and health concerns but shapes a greener future in the industry, creating a synchronized performance of scientific advancement, societal needs, and ecological preservation.