Color Compounds Research Articles

A greener approach to assess bioactive compounds in tropical pumpkin (Cucurbita moschata) using colorimetry

Bioactive compounds have been shown to promote healthy human development and protect against certain diseases including some cancers. Tropical pumpkins bred for consumption, such as calabaza (Cucurbita moschata), possess these compounds, though concentrations vary considerably between varieties. Bioactive compound quantification methods can be expensive, complex, and generate considerable hazardous waste. A predictive tool utilizing the relationship between extrinsic properties and tristimulus colorimetry values of calabaza would allow for significantly higher throughput with lower requirements for equipment, training, and laboratory consumables. Therefore, this study examined correlations between flesh color and bioactive compound quantities of several calabaza germplasm lines to assess the utility of a sustainable and portable predictive tool. CIEL* a* b* values of pumpkin flesh were assessed using a colorimeter and compared to bioactive compound concentrations determined analytically. Redness was found to correlate with increased ascorbic acid and total soluble solids content. Yellowness correlated with β-carotene equivalent carotenoids and ascorbic acid content. These results suggest that colorimetry may be a viable pre-screening technique for quantifying bioactive compounds in C. moschata.

Utilization of Microencapsulated Polyphenols to Enhance the Bioactive Compound Content in Whole Grain Bread: Recipe Optimization

In today’s health-conscious society, there is an increasing consumer demand for functional foods that not only satisfy nutritional needs but also promote overall well-being. The aim of this study was to develop a bread formulation enriched with microencapsulated polyphenols, oat β-glucan concentrate, and sour fermented beetroot juice to enhance its nutritional profile and health benefits. To protect sensitive polyphenols from thermal degradation during baking, the microencapsulation technique was employed to maintain their bioactivity. The influence of these ingredients on the physio-chemical parameters of bread (dough viscosity, hardness, porosity, bioactive ingredients content, color, and volatile compounds profiles), as well as sensory acceptability, was evaluated. Using response surface methodology, the formulation was optimized to achieve a product with high polyphenol and β-glucan content. The optimized formulation included a content of 4.60% sour fermented beetroot juice, 6.29% β-glucan concentrate, and 2.77% microencapsulated polyphenols. The final bread demonstrated significant antioxidant activity and high consumer acceptability, indicating its potential as a functional alternative to traditional bread. This innovative approach addresses the demand for healthier food options and emphasizes the role of functional ingredients in improving dietary quality and promoting health benefits.

Optimization of Production Process of Alcohol Vinegar Macerated With Acai (Euterpe Precatoria) Using RSM to Add Colour and Functional Compounds to Vinegar

In Brazil, the alcohol vinegar is the cheapest vinegar found in the market and it has the lowest nutritional quality. The acai, a native Amazon fruit, is globally recognized as a super fruit and it is highly perishable. Research has been performed to deliver bioactive compounds and to substitute synthetic by the natural colourants in finished foods.

Effect of pulsed light on enzyme inactivation, colour, firmness, surface morphology, and bioactive compounds in fresh and dried whole red chilies (Capsicum annuum var. longum)

The effect of pulsed light on enzymatic activity and biochemical stability of red chillies was investigated. Balancing and reducing the aw and moisture content to 0.6 aw and 0.35 aw is crucial to attain biochemical stability. Upon drying at 60 °C/5 h + 40 °C/2 h and 70 °C/11 h + 55 °C/4 h + 40 °C/2 h the enzymes inactivated to more than 30 %, respectively. Hence, to completely inactivate the enzymes, a technology has been introduced i.e., pulsed light treatment (PLT), which employed 0.53–2.59 J·cm−2. The stability of red chillies was evaluated based on the quality attributes such as enzyme activity, total phenolics, flavonoids, antioxidant capacity, ascorbic acid, capsiacinoids, and carotenoids. After treatment at fluence of 2.59 J·cm−2, there was >90 % inactivation of PPO and POD. Based on kinetic modelling, it is showed PLT better preserved the colour, texture, morphology, and bioactive compounds in 0.6 and 0.35 aw than 0.85 aw red chillies. Morphological studies determined the changes in red chillies after PLT. FTIR and GCMS analysis revealed the structural and compositional changes occurring after PLT. Therefore, drying combined with PL can be a potential alternative method to blanching along with maximizing the availability of bioactives.

Improved preservation of the color and bioactive compounds in strawberry pulp dried under UV-Blue blocked solar radiation

Strawberry (Fragaria ananassa spp.) is a highly preferred fruit because of its health benefits, flavor, fragrance, and color appeal. The drying process for strawberries extends their shelf life but also changes their color and alters their nutritional contents. The anthocyanins are responsible for the color, which are susceptible to degradation during thermal processing, reducing the customer appeal of these food products. The benefit of solar drying of strawberry pulp using UV-Blue blocking optical filters compared with d irect solar drying is presented in this work. Total anthocyanins, antioxidant activity, and the color of the strawberry pulp were monitored as the drying progressed. The UV-Blue blocking optical filter consisted of a copper sulfide/copper selenide thin film of 160 nm in thickness applied on the outer surface of cellular polycarbonate sheets of 8 mm cell-size, 0.1 mm wall thickness (1 kg/m2) cut from sheets measuring 122 cm x 122 cm in area, and protected by a food-safe adhesive polyethylene foil. Total anthocyanins and antioxidant activity were measured using the differential pH and the DPPH (2,2-diphenyl-1-picrilhydrazil) methods. The filter preserves a higher total anthocyanin content and antioxidant activity in the dried product than in the pulp dried under sunlight conditions. A reduced total color change was observed in the product dried under the UV-Blue blocking solar filter. This study highlights a general need to evaluate the bioactive merits of solar dried farm produce to assess the advantage they hold for their commercialization.

Vegetables Treated before Drying with Natural Antioxidants plus UV-C Improve Colour and Bioactive Compounds

The quality of minimally processed fruits and vegetables is essential for consumers’ health and effective marketing. This study investigates the effects of UV-C irradiation, applied alone and combined with various natural antioxidants, on the preservation of bioactive compounds and the colour of dehydrated fruits and vegetables. To achieve this, red peppers, yellow peppers, tomatoes, zucchini, eggplants, and melons were subjected to pre-treatments with natural antioxidants and UV-C before processing using low-temperature airflow (50 °C). The drying kinetics showed typical curves of hygroscopic materials, while the drying time was high due to the low temperature applied. The higher drying rate was found for eggplant, due to its porosity, thus allowing a faster moisture removal. The application of antioxidants and UV-C treatments effectively preserved the colour parameters L*, a*, and b*, while in the case of untreated dried vegetables, a significant worsening of colour parameters was noted. However, most applied pre-treatments had positive effects on bioactive compound losses. The best results were obtained using a combination of UV-C with one antioxidant mix that was composed of vanillin, rosemary, and citrus extracts, and combined with a mixture of olive, onion, garlic, and citric acid extracts, which was highly effective in preserving the colour and bioactive compounds of most dried vegetables.

Morphological Evaluation and Phenolic Content of Wild Prunus cerasifera Ehrh. Fruits from Slovenia

Wild fruit species offer significant nutritional, environmental, and economic benefits. Among them, Prunus cerasifera Ehrh. (myrobalan) stands out for its resilience and nutrient-rich fruits, traditionally consumed fresh or dried. This study aimed to assess the morphological and biochemical diversity of 21 wild P. cerasifera accessions from Slovenia, focusing on 18 fruit and stone traits, including size, shape, color, and phenolic compounds such as total monomeric anthocyanins and total phenolic content (TPC). The objective was to identify genotypes with potential for cultivation and food production or as parental components in breeding programs. The results showed variability in fruit length (2.19–2.82 cm), width (2.18–2.99 cm), weight (67.98–150.30 g), firmness, and juiciness, with notable differences in stone characteristics. Phytochemical analysis revealed a wide range of TPC (277–1756 mg/100 g) and anthocyanin levels (0–710 mg/100 g), with higher concentrations in darker fruits. Statistical analysis compared PAM and AGNES clustering methods, finding that PAM with five clusters and AGNES with two clusters provided similar insights. The study emphasized variability in morphological and chemical traits among clusters, with specific accessions showing particularly valuable traits, such as accession RK13, which had high TPC and anthocyanins and a non-adherent stone.

Перспективы комплексной переработки ягод черной смородины

Black currant (Ribes nigrum L.) is one of the most popular berries in Russia. Its biochemical properties make it part of a healthy diet. This review describes the role of black currant and its by-products in the food industry and defines its nutritional value, i.e., vitamin C, anthocyanins, and dietary fiber. It covered original Russian and English research articles and reviews published in 2015-2023 and indexed in the Russian Research Citation Index or Pubmed databases. The keywords were black currant in Russian and English. Black currant berries are rich in dietary fiber, polyphenolic compounds, anthocyanins, vitamin C, and potassium. They cover human needs for these nutrients. Added to fermented dairy and grain foods at 5-20%, fresh or processed berries fortify them with dietary fiber, vitamin C, and anthocyanins while reducing energy value. As ingredients with color, taste, and aromatic compounds, black currant berries and their secondary products can be introduced into the formulations of various alcoholic beverages. Berry pomace is a technologically functional ingredient with a moisture-retaining ability that increases the antioxidant capacity of the final product. Juice and aqueous extracts of black currant pomace are used as picklers for fish and meat products to increase their microbiological safety and shelf-life. Complex processing of black currant berries is feasible as they are a valuable source of dietary fiber, vitamin C, and anthocyanins. Products of their processing provide a concentrate of dietary fiber with natural antioxidants. However, functional foods as sources of biologically active substances need to follow special criteria for fortified products. Black currant and its by-products are a potential source of valuable biologically active substances. In small quantities, they can expand the range of food products but fail to satisfy human diet with biologically active substances or reduce the overall energy value.

Evaluation of a Sustainable Production of Encapsulated Chili Pepper Powder (Capsicum pubescens) through Convective and Vacuum Drying

Throughout the world, chili and chili powders are spices of considerable economic importance. Rocoto (Capsicum pubescens R. & P.) is a chili pepper used in Andean cuisine. Fresh chili is perishable and therefore it is convenient to protect the capsaicin, color and other bioactive compounds through preservation methods such as encapsulation. The present study systematically evaluates the technical and environmental aspects of producing encapsulated Rocoto red chili powder using three different wall materials—maltodextrin, rice protein and rice flour—in conjunction with two drying methods, namely convection drying and vacuum drying. Our technical objectives focused on developing an encapsulated product with high heat and vibrant red color, key attributes that significantly influence consumer purchasing behavior. In addition, the study aimed to mitigate the loss of polyphenols, flavonoids and antioxidant activity. After identifying the optimal conditions for each wall material and drying process, a comprehensive environmental assessment was conducted to identify the most efficient and sustainable production methods. The results demonstrate that rice flour encapsulation (20%) in conjunction with hot air drying (40 °C) represents the most efficacious method for the preservation of chili powder’s pungency. This approach resulted in a mere 24% reduction in Scoville units while maintaining the powder’s vibrant red coloration. This method not only preserved key bioactive compounds, including capsaicin, polyphenols and flavonoids, but also significantly enhanced the antioxidant capacity of the product. From an environmental perspective, this approach offers significant sustainability benefits, reducing the overall environmental impact by approximately 72% compared to vacuum drying of unencapsulated chili. The use of rice flour as an encapsulant aligns with sustainability goals, making it the most efficient option for balancing product quality and environmental performance.

Integrated processes for olive mill wastewater treatment and its revalorization for microalgae culture.

The olive oil industry generates 30 million cubic meters of olive mill wastewaters (OMWWs) annually. OMWWs are a major environmental concern in the Mediterranean region due to their high organic matter content, suspended solids, unpleasant odor, and dark color. The application of primary treatments such as coagulation-flocculation, adsorption, and hybrid systems combining coagulation-flocculation with adsorption has enabled to remove part of the organic matter, color, turbidity, and growth-inhibiting compounds from OMWWs. Among these methods, the hybrid system combining activated carbon and chitosan has proven to be the best removal efficiency. Subsequently, secondary treatment involving the cultivation of Chlorella sp. on OMWWs pretreated with chitosan achieved the highest maximal specific growth rate (0.513 ± 0.022day⁻1) and biomass productivity (0.621 ± 0.021g/L/day). Notably, the fatty acids (FA) profile produced by Chlorella sp. cells grown under these conditions differed, underscoring the potential of OMWWs as a microalgal growth medium. This innovative approach not only addresses environmental issues but also opens new avenues for sustainable bioproducts.

Comparison of different drying technologies for green tea: Changes in color, non-volatile and volatile compounds

Drying technology plays a pivotal role in tea processing. Herein, the differences in color, non-volatile, and volatile components of green tea under various drying methods were investigated. The results indicated that vacuum freeze-microwave increased the L* and b* values, and decreased the a* values of tea leaves. Moreover, vacuum freeze-microwave drying resulted in higher polyphenol content than the other three drying methods although there was no significant difference. A total of 43 volatile compounds were identified. Of these, 2-propanone, ethanol(D), ethanol(M), ethyl acetate(M), 2-methyl-1-butanol, and 2-methylthiophene were found to play an important role in the above discrimination (VIP >1.5). Dry extraction showed a higher content of volatile components than wet extraction. Regardless of the extraction conditions, vacuum freeze-microwave drying exhibited a stronger signal intensity and more volatile components than other drying methods. This study provides a reference for analyzing the quality differences of green tea by different drying methods.

Isolation of linalool compounds of nampu rhizome essential oil (Homalomena occulta) by vacuum fractionation distillation method

The perfume industry in various countries is increasingly expanding and the appeal of perfume comes from its distinctive scent. One of Indonesia's potential needs in the organic perfume industry is essential oils. Nampu rhizome (Homalomena occulta) has great potential and is widely spread on the island of Java. This is because the Nampu rhizome has the main chemical component in the form of linalool compounds, which are essential oil components with high economic value, so it needs to improve quality by increasing its purity. A technology that was developed to improve the purity of essential oils was vacuum fractionation distillation. The purpose of the study was to analyze the effect of temperature on the quality of distillation in the fractionation results of Nampu rhizome essential oil (linalool compound). The experiment used a material temperature factor between 135-160°C and > 160°C.The analysis of fractionation results was carried out on physical properties including refractive index, specific gravity, optical rotation, colour, and linalool compound with GC-FID and yield. The results showed a refractive index value of 1.4620 nD, specific gravity of 0.8647, optical rotation of -19.80, clear oil colour and yield of 69.80%. Chemical analysis with GC-FID improves the purity level of the final product against the linalool fraction increased by 10.02% or linalool purity by 90.92%.

Impact of roasting time on the color, protein, water distribution and key volatile compounds of pork

The study aimed to determine the changes in physical and chemical indicators in pork during the roasting process and establish predictive models for industrial intelligent production in the future, the effects of roasting times (0–15 min) on the dynamic changes in the surface color, water, protein and the volatile compounds in pork were investigated. The results showed that during the roasting process, the L* value increased firstly (0–3 min) and then decreased (3–15 min), the a* value decreased firstly (0–12 min) and then increased (12–15 min), while the b* value increased (0–15 min). A total of 29 volatile compounds were identified by gas chromatography–mass spectrometry, 11 volatile differentiators were identified by partial least squares-discriminant analysis, and 14 key volatile compounds were selected by odor activity values analysis. The total water content significantly decreased and the water in meat migrated from high degrees of freedom to low degrees of freedom. Roasting for 6 min was a key turning point in the changes of the α-helix, β-sheet and random coil. In addition, SDS-PAGE analysis, and the changes in the contents of carbonyl, total and free sulfhydryl verified proteins oxidation in the pork during the roasting process.

Quality analysis and assessment of representative sea buckthorn fruits in northern China

Sea buckthorn (SB) primarily grows in northern China and is rich in nutritional components, making it popular among consumers. This study aims to select suitable SB varieties for processing by analyzing physicochemical components, color, taste, and volatile compounds. The results showed that the physicochemical content of Chinese SB from Gansu were as follows: total soluble solids 13.50 ± 0.37°Brix, titratable acidity 6.46 ± 0.39 %, ascorbic acid 578 mg/100 g, polyphenols 517 mg/100 g, and flavonoids 194 mg/100 g, which were higher than those of the other four SB samples; the content of organic acids was relatively abundant. Taste analysis via electronic tongue indicated that Chinese SB had the highest ANS (sweetness) value and the lowest SCS (bitterness) value, exhibiting the richest flavor. Gas chromatography-mass spectrometry analysis showed that Gansu Chinese SB had a rich variety of volatile components, totaling 74. In summary, Gansu Chinese SB is a variety suitable for processing.

From waste to wellness: a review on the harness of food industry by‐products for sustainable functional food production

SummaryThe production of functional foods has been on a consistent rise in the past few years. The increasing demand for these foods could play a pivotal role in addressing the escalating issue of food waste and in the creation of innovative food formulations. Utilising by‐products from the food industry has become commonplace due to their advantageous nutritional composition and functional properties. These by‐products retain richness in colour compounds, proteins, amino acids, lipids, fatty acids, sugars, fibres, minerals, vitamins, antioxidants and antimicrobial compounds. This abundance of elements can be harnessed to develop innovative food products. This review examines the potential of utilising food industry wastes for producing functional foods, focusing on residues from animal and vegetable origins; such residues find application in creating snacks, beverages, fermented foods, bakery items, dairy products, pasta, charcuterie, chocolate, flavouring agents, additives and culinary innovations. This study seeks to establish a sustainable strategy for minimising food waste disposal, fostering a bio‐based food production industry and enhancing overall sustainability by uncovering alternatives for novel, nutritious and value‐added food products.

Lactic acid bacteria‐fermented Chlamydomonas reinhardtii as an innovative ingredient to produce microalgae‐enriched steamed bread

AbstractBackground and ObjectivesChlamydomonas reinhardtii (C. reinhardtii) is recognized as a sustainable source of high‐quality protein. This study aimed to assess the potential application of C. reinhardtii for producing microalgae‐fortified steamed bread. To reduce the inherent green color and volatile compounds of the microalgae, lactic acid bacteria (LAB) fermentation was applied as a pretreatment method for C. reinhardtii. Subsequently, both unfermented (unFC) and fermented C. reinhardtii (FC) were added to steamed bread formulations (4%, 8%, 12%, and 16% wheat flour substitution).FindingsThe results showed that the incorporation of unFC into steamed bread had a dose‐dependent negative impact on the dough fermentation performance and the quality of steamed bread, including volume, texture, and sensory attributes, rendering the steamed bread unacceptable. Fermentation altered the amino acid profile of C. reinhardtii, caused the color to shift from green to red (a*, −14.7 vs. 7.0), and reduced unpleasant volatile components. Further, fermentation reduced the negative impact of microalgae incorporation, especially at substitution levels of 4% and 8%, which manifested as an increased dough fermentation volume and improved bread volume with reduced crumb firmness of the steamed bread. However, in sensory analysis, the steamed bread that contained 4% FC had an overall acceptability similar to the control sample.ConclusionsMicroalgae‐enriched steamed bread could be produced by incorporating up to 4% FC to improve its nutritional profiles while maintaining overall sensory acceptability by the consumers.Significance and NoveltyLAB fermentation of C. reinhardtii is a feasible strategy to address the sensory and structural challenges that hinder the incorporation of algae into food products.

Selected Soluble Dietary Fibres as Replacers of Octenyl Succinic Anhydride (OSA) Starch in Spray-Drying Production of Linseed Oil Powders Applied to Apple Juice

The aim of the study was to compare two kinds of soluble dietary fibres in a mixture with OSA-starch as wall components of linseed oil capsules. Comparison was made based on emulsion (droplet size, polydispersity index, and viscosity) and powder properties (outer structure, colour, surface oil content, and encapsulation efficiency). Additionally, linseed oil powders were applied to the food model (apple juice) and the colour, physical stability, and volatile compound profile of fortified juice were determined. Although the obtained linseed oil emulsions with different compositions of polysaccharide components showed some variation in droplet size, polydisperse index and viscosity, their encapsulation efficiency by spray-drying was very high (>98%). The powders produced had a similar structure and low surface oil content, and their 2% addition to apple juice did not change its stability and only slightly decreased its colour lightness and yellowness. However, greater differences in the volatile compounds of obtained juices were observed. Overall, the added powders reduced the volatility of aroma compounds typical of apple juice but introduced propanal and hexanal, especially the powders with the highest OSA-starch share.

Study of Ultrasound-Assisted Technology for Accelerating the Aging Process in a Sugar Cane Honey Spirit

This study aims to obtain an alternative aging method using toasted white oak chips and ultrasound technology that yields a final product of similar quality to the one obtained by a traditional aging system in reduced time. Different conditions of ultrasound treatment and ethanol concentration during the maturation stage were studied. A sugar cane honey spirit was produced. The ultrasound treatments were applied to the distilled product to extract the color, aroma, and flavor compounds from the white oak chips used. Trials of spectrophotometry-evaluated color and e-sensing technology were applied to assess flavor and aroma. Very distinct color changes were obtained, indicating that ultrasound treatment facilitates the extraction of color compounds from the oak chips. The flavor profile obtained was similar to the one obtained for the unaged reference, indicating that the accelerated aging treatment may not influence flavor in a significant manner. The aroma profile achieved most descriptors found in the commercial rum aroma profile, indicating that the aging method studied influences the aroma profile. In general, the methods used allowed us to produce an aged spirit, offering a reduction in maturation time over the traditional system and a similar sensory profile for the final product.

Study of liquid photopolymer 3D printing resins exposed to accelerated aging for cultural heritage purposes

PurposeThis paper aims to study the suitability of a selection of 3D printing liquid photopolymer resins for their application in the cultural heritage context.Design/methodology/approachThe main concerns regarding the conservation and restoration of cultural assets are the chemical composition and long-term behavior of the new materials that will be in contact with the original object. Because of this, four different LED curing resins were exposed to an accelerated aging procedure and tested to identify the materials which demonstrated a better result. Some specific properties of the material (color, glossiness, pH and volatile organic compound emissions) were measured before and after the exposure.FindingsSome of the properties measured reported good results demonstrating a decent stability against the selected aging conditions. The main changes were produced in the colorimetric aspect, probably indicating other chemical reactions in the material. Likewise, a case study could be also executed to demonstrate the usefulness of these materials in the cultural field.Research limitations/implicationsIt is necessary to study in more detail the long-lasting behavior of the materials employed with these technologies. Further analysis should be carried out highlighting the chemical composition and degradation process of the materials proposed.Originality/valueThis paper contributes to the introduction of curing 3D printing resins in the restoration methodologies of cultural assets. For this, the study of a selection of properties represents the first stage to suggest or reject their use.

Exploring the relationship between color and taste: Unveiling critical color and taste compounds of Qingxiang Tieguanyin tea infusion

The color and taste of tea infusion play crucial roles in assessing tea quality. While color can be easily quantified, taste perception is subjective in nature. Can the color of tea infusion directly reflect its taste? In this study, spectroscopy and metabolomics techniques combined with machine learning algorithms, were used to identify the key compounds that responsible for both color and taste in Qingxiang Tieguanyin (QXTGY) tea infusion. The results showed strong correlations between almost all of 46 differential compounds and the taste profile of the tea infusion. Notably, quercetin 3-O-glucosyl rutinoside, rutin, and quercetin 3-O-glucoside were found to establish a connection between the color and taste of QXTGY tea infusion. Specifically, within a certain range, these compounds promoted a darker color (deepening the yellowness) in the tea infusion while simultaneously reducing its umami and brisk taste. This indicates that the color of tea infusion can reflect its taste to some extent. Furthermore, quercetin 3-O-glucosyl rutinoside had the most significant impact on the color of the tea infusion. The findings of this study offer an alternative objective approach to evaluate the taste of tea infusion by objectively determining its color.