Phytochemical Characterization of Citrus-Based Products Supporting Their Antioxidant Effect and Sensory Quality

Citrus reticulata Olive Oil: Production and Nutraceutical Effects on the Cardiovascular System in an In Vivo Rat Model of Metabolic Disorder

Recently, there has been significant exploration into the utilization of food by-products as natural reservoirs of bioactive substances, particularly in the creation of functional foods naturally enriched with antioxidants. Citrus peels represent a viable option for formulating enhanced olive oils that contribute to a healthier diet, due to their bioactive compound content. This study aimed to (i) ascertain the compositional characteristics of Citrus reticulata olive oil (CrOO) and (ii) assess its nutraceutical properties in rats with metabolic disorder induced by 3 weeks of feeding with a high-fat diet (HFD). The results showed a peculiar phytochemical composition, thanks to the contribution of citrus peels, which are excellent bio-products. In addition, it demonstrated HFD-induced weight gain (18 ± 2% for HFD vs. 13 ± 0.9% for CrOO) and showed protective effects on fasting blood glucose levels (90.2 ± 3.8 mg/dL for HFD vs. 72.3 ± 2.6 for CrOO). Furthermore, a reduction in cardiovascular risk (total cholesterol/HDL cholesterol = 5.0 ± 0.3 for HFD vs. 3.8 ± 0.3 for CrOO) and an improvement in myocardial tissue function were observed, as well as a significant reduction in inflammatory mediators such as iNOS, COX-2, and mPGES-1 in aortic vessel tissues, thus preserving endothelial function at the vascular level.

Integrated HS-GC-IMS and UPLC-Q-Orbitrap HRMS-based metabolomics revealed the characteristics and differential volatile and nonvolatile metabolites of different citrus peels

Citrus is an important genus in the Rutaceae family, and citrus peels can be used in both food and herbal medicine. However, the bulk of citrus peels are discarded as waste by the fruit processing industry, causing environmental pollution. This study aimed to provide guidelines for the rational and effective use of citrus peels by elucidating the volatile and nonvolatile metabolites within them using metabolomics based on headspace-gas chromatography-ion mobility spectrometry and ultra-high-performance liquid chromatography-Q-Orbitrap high-resolution mass spectrometry. In addition, the antioxidant activities of the citrus peels were evaluated using DPPH radical scavenging, ABTS radical scavenging, and ferric reducing antioxidant power. In total, 103 volatile and 53 nonvolatile metabolites were identified and characterized. Alcohols, aldehydes, and terpenes constituted 87.36% of the volatile metabolites, while flavonoids and carboxylic acids accounted for 85.46% of the nonvolatile metabolites. Furthermore, (Z)-2-penten-1-ol, L-pipecolinic acid, and limonin were identified as characteristic components of Citrus reticulata Blanco cv. Ponkan (PK), C. reticulata 'Unshiu' (CLU), and C. reticulata 'Wo Gan' (WG), respectively. Principal component analysis and partial least squares discriminant analysis indicated that C. reticulata Blanco 'Chun Jian' (CJ), PK, CLU, and C. reticulata 'Dahongpao' (DHP) were clustered together. DHP is a traditional Chinese medicine documented in the Chinese Pharmacopoeia, suggesting that the chemical compositions of CJ, PK, and CLU may also have medicinal values similar to those of DHP. Moreover, DHP, PK, C. reticulata 'Ai Yuan 38'(AY38), CJ, C. reticulata 'Gan Ping'(GP), and C. reticulata 'Qing Jian'(QJ) displayed better antioxidant activities, recommending their use as additives in cosmetics and food. Correlation analysis suggested that some polyphenols including tangeritin, nobiletin, skullcapflavone II, genistein, caffeic acid, and isokaempferide were potential antioxidant compounds in citrus peel. The results of this study deepen our understanding of the differences in metabolites and antioxidant activities of different citrus peel varieties and ultimately provide guidance for the full and rational use of citrus peels.

Towards Sulphite-Free Winemaking: A New Horizon of Vinification and Maturation

The complex dynamics between oxygen exposure, sulphur dioxide (SO2) utilization, and wine quality are of the utmost importance in wine sector, and this study aims to explore their fine balance in winemaking. As a common additive, SO2 works as an antiseptic and antioxidant. However, its excessive use has raised health concerns. Regulatory guidelines, including Council Regulation (EC) N° 1493/1999 and Commission Regulation (EC) No 1622/2000, dictate SO2 concentrations in wines. The increasing demand for natural preservatives is driving the search for alternatives, with natural plant extracts, rich in phenolic compounds, emerging as promising substitutes. In this context, Bioma Company has proposed alternative additives deriving from vineyard waste to replace SO2 during winemaking. Thus, the aim of the present work was to compare the compositional characteristics between the product obtained with the alternative vinification and the traditional one during the winemaking, as well as the aroma compositions of the final wines. After a year of experimentation, the wines produced with Bioma products showed compositional characteristics comparable to their traditional counterparts. Notably, these wines comply with current legislation, with significantly reduced total sulphur content, allowing their designation as "without added sulphites". Bioma products emerge as potential catalysts for sustainable and health-conscious winemaking practices, reshaping the landscape of the industry.

Chemical Composition, Functional and Antioxidant Properties of Dietary Fibre Extracted from Lemon Peel after Enzymatic Treatment

Lemon peel represents an interesting by-product owing to its content of dietary fibre (DF) and (poly)phenols, which is of great importance for its valorisation. Hence, the objective of this study was to characterise the DF, total phenolic content (TPC), and antioxidant capacity of two lemon-peel-derived ingredients using two different methods (drying with warm air and enzymatic hydrolysis with pectinesterase). The analysis included a DF assessment, followed by neutral sugars characterisation through GC-FID and uronic acids determination via colorimetry. Subsequently, TPC and antioxidant capacity using the FRAP method were quantified through spectrophotometry. The swelling capacity (SWC), water retention capacity (WRC), and fat absorption capacity (FAC) were also determined as functional properties. It was observed that pectinesterase treatment led to a reduction in soluble DF and an increase in insoluble DF. This treatment also affected the pectin structure, thereby diminishing its ability to absorb water and fat within its matrix. The TPC was also reduced, resulting in a decrease in antioxidant capacity. Conversely, employing warm air exhibited a noteworthy increase in antioxidant capacity. This underscores its crucial contribution to the valorisation of lemon peel, not only by diminishing the environmental impact but also by enabling the acquisition of fibre ingredients with a noteworthy antioxidant capacity.

Functional Ingredients and Additives from Lemon by-Products and Their Applications in Food Preservation: A Review

Citrus trees are among the most abundant fruit trees in the world, with an annual production of around 124 million tonnes. Lemons and limes are among the most significant contributors, producing nearly 16 million tonnes per year. The processing and consumption of citrus fruits generates a significant amount of waste, including peels, pulp, seeds, and pomace, which represents about 50% of the fresh fruit. Citrus limon (C. limon) by-products are composed of significant amounts of bioactive compounds, such as phenolic compounds, carotenoids, vitamins, essential oils, and fibres, which give them nutritional value and health benefits such as antimicrobial and antioxidant properties. These by-products, which are typically discarded as waste in the environment, can be explored to produce new functional ingredients, a desirable approach from a circular economy perspective. The present review systematically summarizes the potential high-biological-value components extracted from by-products to achieve a zero-waste goal, focusing on the recovery of three main fractions: essential oils, phenolic compounds, and dietary fibres, present in C. limon by-products, and their applications in food preservation.

Characterization of the endophytic bacterial community of Bituminaria bituminosa plant grown in vitro and its interaction with the plant extract

INTRODUCTION

Bituminaria bituminosa is a medicinal plant recognized for its phytochemicals, such as furanocoumarins, pterocarpans, and flavonoids. Since the secondary metabolism is influenced by the plant-endophyte interactions, the endophytic bacterial community of B. bituminosa was explored and the possible interactions with the plant were described.

MATERIALS AND METHODS

Different bacterial strains were isolated from different organs of in vitro plants as shoots, roots, and seeds. The bacterial strains were identified and phenotypically characterized for different traits; strains were also exposed to different concentrations of B. bituminosa plant extract showing different susceptibility, probably determined by different secondary metabolites produced by the plant in the different organs (i.e. aerial parts and roots).

RESULTS AND DISCUSSION

Bacterial strains showed different phenotypic characteristics; the 6 detected haplotypes were dominated by a single species related to Stenotrophomonas rhizophila. Endophytes isolated from the aerial parts produced a higher indole-3-acetic acid (IAA) amount than those of the roots, while all strains were unable to produce biosurfactants and antagonistic activity toward the other strains. The research opens new perspectives for future analysis addressed to test the susceptibility of the endophytic bacterial community of B. bituminosa toward the pure compounds extracted from the plants, and to investigate the role of these compounds on the distribution of endophytes within the different plant tissues.