Enzyme-Assisted Extraction for the Recovery of Food-Grade Chlorophyll-Based Green Colorant

Stabilized chlorophyll-based food colorants from spinach: Kinetics of a tailored enzymatic extraction

An organic solvent-free method based on limited dosing options (biocatalyst and zinc chloride) for the quick and mild recovery of chlorophyll (Chl) from spinach has been proposed. This tailored, custom-made protocol has been designed to produce stable green natural colorants. The kinetics of pigment extraction turned out to be a very useful tool to identify the proper conditions, in terms of biocatalyst dose (0.10-50 U/g), extraction time (1-48h), and ZnCl2 amount (50-300ppm), both for enhancing the recovery yield and preserving the green color. Considering the extraction kinetics, the recovery yield, and the colorimetric data, the suitable conditions to produce stable green and food-grade colorants are 0.10 U/g of enzyme, 3h, and 150ppm of ZnCl2 at 25°C. The extraction yield of Chl (4863µg/U) was about 51% greater than control, with a higher extraction rate constant (5.43 × 10-4 g/(µg min)). Considering the impact of ZnCl2 amount on Chl, its protective action resulted to be more noticeable toward Chl a: at 150ppm, an increased amount of about 2.5 and 1.5 times was found for Chl a and Chl b, respectively, in comparison to the reference (0ppm ZnCl2). PRACTICAL APPLICATION: This research demonstrates how a suitable kinetic approach helps to provide a tailored protocol, customized for the vegetable matrix, to produce stable green natural colorants from spinach. Lowering enzyme dosage and ZnCl2 amount during the extraction of chlorophyll at low temperature is crucial for its potential use as a colorant in food industry, providing high economic values through saving time and environmental protection.

Natural Pigments Recovery from Food By-Products: Health Benefits towards the Food Industry

Given the health risks associated with synthetic colorants, natural pigments have emerged as a promising alternative. These renewable choices not only provide health benefits but also offer valuable technical and sensory properties to food systems. The effective application of natural colorants, however, requires the optimization of processing conditions, exploration of new sources, and development of novel formulations to ensure stability and maintain their inherent qualities. Several natural pigment sources have been explored to achieve the broad color range desired by consumers. The purpose of this review is to explore the current advances in the obtention and utilization of natural pigments derived from by-products, which possess health-enhancing properties and are extracted through environmentally friendly methods. Moreover, this review provides new insights into the extraction processes, applications, and bioactivities of different types of pigments.

Combined Effects of Polystyrene Nanosphere and Homosolate Exposures on Estrogenic End Points in MCF-7 Cells and Zebrafish

BACKGROUND

Micro- and nanoplastics (MNPs) and homosalate (HMS) are ubiquitous emerging environmental contaminants detected in human samples. Despite the well-established endocrine-disrupting effects (EDEs) of HMS, the interaction between MNPs and HMS and its impact on HMS-induced EDEs remain unclear.

OBJECTIVES

This study aimed to investigate the influence of MNPs on HMS-induced estrogenic effects and elucidate the underlying mechanisms in vitro and in vivo.

METHODS

We assessed the impact of polystyrene nanospheres (PNSs; 50  nm , 1.0 mg / L ) on HMS-induced MCF-7 cell proliferation (HMS: 0.01 - 1 μ M , equivalent to 2.62 - 262 μ g / L ) using the E-SCREEN assay and explored potential mechanisms through transcriptomics. Adult zebrafish were exposed to HMS (0.0262 - 262 μ g / L ) with or without PNSs (50  nm , 1.0 mg / L ) for 21 d. EDEs were evaluated through gonadal histopathology, fertility tests, steroid hormone synthesis, and gene expression changes in the hypothalamus-pituitary-gonad-liver (HPGL) axis.

RESULTS

Coexposure of HMS and PNSs resulted in higher expression of estrogen receptor α (ESR1) and the mRNAs of target genes (pS2, AREG, and PGR), a greater estrogen-responsive element transactivation activity, and synergistic stimulation on MCF-7 cell proliferation. Knockdown of serum and glucocorticoid-regulated kinase 1 (SGK1) rescued the MCF-7 cell proliferation induced by PNSs alone or in combination with HMS. In zebrafish, coexposure showed higher expression of SGK1 and promoted ovary development but inhibited spermatogenesis. In addition, coexposure led to lower egg hatchability, higher embryonic mortality, and greater larval malformation. Coexposure also modulated steroid hormone synthesis genes (cyp17a2, hsd17[Formula: see text]1, esr2b, vtg1, and vtg2), and resulted in higher 17 β -estradiol (E 2 ) release in females. Conversely, males showed lower testosterone, E 2 , and gene expressions of cyp11a1, cyp11a2, cyp17a1, cyp17a2, and hsd17[Formula: see text]1.

DISCUSSION

PNS exposure exacerbated HMS-induced estrogenic effects via SGK1 up-regulation in MCF-7 cells and disrupting the HPGL axis in zebrafish, with gender-specific patterns. This offers new mechanistic insights and health implications of MNP and contaminant coexposure. https://doi.org/10.1289/EHP13696.