Bioactive Substances, Heavy Metals, and Antioxidant Activity in Whole Fruit, Peel, and Pulp of Citrus Fruits

Determination of trace elements content of fruits from Tehran's market using ICP- OES method: a risk assessment study

For the first time in Iran, in this study, the amount of 19 trace elements in some types of commonly consumed Iranian fruits (in their peel and pulp) was evaluated by ICP-OES (Inductively coupled plasma-optical emission spectrometry) method. Based on the outcomes, the highest and lowest average detected elements in all fruits samples were related to (Al) aluminum (1842.18) and (V) vanadium (0.28) ppm, respectively. Mercury (Hg) and antimony (Sb) were not detected (ND) in any samples. Also, the maximum mean of elements in quince, lemon, grapefruit, kiwi, orange south, orange north and tangerine samples was related to(Fe) iron (2048.32 ppm), (Zn)zinc(753.45 ppm), Fe (1056.33 ppm), Al (9794.41 ppm), Zn (717.78 ppm), Fe (1334.87 ppm) and Fe (974.93 ppm), respectively. Furthermore, our outcomes revealed, the highest mean of elements in kiwi peel, kiwi pulp, orange North peel, orange North pulp, orange South peel, orange South pulp, quince peel, quince pulp, grapefruit peel, grapefruit pulp, lemon peel, lemon pulp, tangerine peel and tangerine pulp was related to Al (17967.79 ppm), Al (1621.03 ppm), Fe (1350.01 ppm), Al (1457.66 ppm), Zn (934.71 ppm), Fe (728.06 ppm), Fe (2768.11 ppm), Fe (1328.54 ppm), Zn (1008.54 ppm), Fe (1198.00 ppm), Zn (683.35 ppm), Zn (823.55 ppm), Fe (1182.59 ppm), and Fe (767.27 ppm), respectively. Based on the Monte Carlo simulation results, the THQ (target hazard quotient) and ILCR (Incremental Lifetime Cancer Risk) related to exposure to heavy metals via fruits for adults and children showed that there is no significant non-carcinogenic risk (THQ < 1) and carcinogenic risk (ILCR < 1E-4) for adults and children.

From food waste to eco-friendly functionalized polymer composites: Investigation of orange peels as active filler

The development of eco-friendly polymer composites with multifunctional properties aligns with the goals of the circular economy agenda, which aims to minimize waste and promote the sustainable use of resources by closing the loop of product life cycles. Eco-friendly polymer composites play a crucial role in achieving these objectives. The present work focuses on the preparation of fully biobased blends obtained by melt mixing a bio-polyester, poly(butylene succinate-co-adipate) (PBSA), with orange peels up to 20 wt%, to yield active polymer composites. Orange peels, employed here as natural filler, are largely available from food wastes, they are rich in phenolic compounds and possess antioxidant activity as shown by the experimental tests carried out. The thermal stability of the formulated composites is almost unchanged by the filler addition, showing only a slight decrease of the crystallization temperatures and crystalline fraction within the composites. The mechanical properties of the compounds evidence an increase in the elastic modulus together with a decrease in the tensile strength, while the elongation at break remains almost constant. The incorporation of the natural filler enabled the integration of antioxidant and antibacterial properties, which were absent in the original pristine polymer.

Trends and challenges of fruit by-products utilization: insights into safety, sensory, and benefits of the use for the development of innovative healthy food: a review

A significant portion of the human diet is comprised of fruits, which are consumed globally either raw or after being processed. A huge amount of waste and by-products such as skins, seeds, cores, rags, rinds, pomace, etc. are being generated in our homes and agro-processing industries every day. According to previous statistics, nearly half of the fruits are lost or discarded during the entire processing chain. The concern arises when those wastes and by-products damage the environment and simultaneously cause economic losses. There is a lot of potential in these by-products for reuse in a variety of applications, including the isolation of valuable bioactive ingredients and their application in developing healthy and functional foods. The development of novel techniques for the transformation of these materials into marketable commodities may offer a workable solution to this waste issue while also promoting sustainable economic growth from the bio-economic viewpoint. This approach can manage waste as well as add value to enterprises. The goal of this study is twofold based on this scenario. The first is to present a brief overview of the most significant bioactive substances found in those by-products. The second is to review the current status of their valorization including the trends and techniques, safety assessments, sensory attributes, and challenges. Moreover, specific attention is drawn to the future perspective, and some solutions are discussed in this report.

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.

Pomelo peel dietary fiber ameliorates alterations in obesity-related features and gut microbiota dysbiosis in mice fed on a high-fat diet

Pomelo peel has abundance of dietary fiber and various biological activities but is often discarded as waste. This study evaluated the biological activities of pomelo peel dietary fiber (PPDF) in preventing obesity and regulating intestinal microbiota in obese mouse model induced using a high-fat diet (HFD). As for the composition, the prepared PPDF contained 89.64% of total dietary fiber, 53.27% of insoluble dietary fiber, and 36.37% of soluble dietary fiber. PPDF treatment significantly reduced weight gain and fat accumulation in the liver and epididymal tissues of obese mice; significantly alleviated HFD-induced dyslipidemia; and restored the levels of triglycerides, low-density lipoprotein-cholesterol, and high-density lipoprotein--cholesterol to control levels, and the PPDF 5% dose restored total cholesterol to the control level. Furthermore, PPDF ameliorated HFD-induced gut microbiota dysbiosis by increasing intestinal microbial diversity, decreasing the Firmicutes/Bacteroidetes ratio, increasing beneficial bacteria (Bifidobacterium, Alloprevotella, and Lactobacillus), and decreasing harmful bacteria (Staphylococcus and Corynebacterium_1). This study provided a new idea to use PPDF as functional food to prevent obesity, alleviate dyslipidemia, or a potential probiotic to ameliorate gut microbiota dysbiosis.

Differential analysis of phytochemistry and antioxidant activity in five citrus by-products based on chromatography, mass spectrometry, and spectrum-effect relationships

The unripe fruit or peel of Citrus aurantium L., Citrus sinensis Osbeck, and Citrus reticulata Blanco are often disregarded due to perceptions of their marginal value. The present study was undertaken to explore the differences in phytochemical composition and bioactive properties of five citrus by-products in China and demonstrate their potential value. 214 compounds were systematically identified using LC-Orbitrap-MS analysis. Among them, narirutin, naringin, hesperidin, and neohesperidin were established as essential compounds for the discrimination and authentication of the five by-products via a combination of LC-MS, HPLC, and TLC techniques. Variations in the antioxidant activity of the by-products were observed, which correlated with their maturity and were attributable to differences in their active ingredients. Moreover, spectrum-effect relationship analysis revealed that the four previously identified differential markers, along with nobiletin and tangeretin, significantly contributed to the differences in antioxidant activity. The results highlight the potential for citrus by-product enhancement and utilization.

Fruit quality assessment based on mineral elements and juice properties in nine citrus cultivars

Introduction

Citrus fruit is considered a superfood due to its multiple nutritional functions and health benefits. Quantitative analysis of the numerous quality characteristics of citrus fruit is required to promote its sustainable production and industrial utilization. However, little information is available on the comprehensive quality assessment of various fruit quality indicators in different citrus cultivars.

Methods

A total of nine different fresh citrus fruits containing seeds were collected as the experimental materials. The objectives of this study were: (i) to determine the morphological and juice properties of citrus fruits, (ii) to measure the mineral elements in the peel, pulp, and seeds, and (iii) to evaluate the fruit quality index (FQI) using the integrated quality index (IQI) and the Nemoro quality index (NQI) methods.

Results

There were significant differences in fruit quality characteristics, including morphological, mineral, and juice quality, among the investigated citrus cultivars. The proportion of pulp biomass was the highest, followed by that of peel and seeds. N and Cu had the highest and lowest concentrations, respectively, among the measured elements across all citrus fruits, and the amounts of N, P, Mg, Cu, and Zn in seeds, K and Al in pulp, and Ca, Fe, and Mn in peel were the highest, dramatically affecting the accumulation of minerals in the whole fruit and their distribution in various fruit parts. Additionally, Ningmeng fruits had the highest vitamin C and titratable acidity (TA) but the lowest total soluble solids (TSS) and total phenolic (TP) contents, resulting in the lowest TSS/TA and pH values. In contrast, Jinju fruits had the highest TSS and TP contents. Based on the mineral element and juice quality parameters, principal component analysis showed that the citrus fruits were well separated into four groups, and the dendrogram also showed four clusters with different distances. The FQI range based on the IQI method (FQIIQI) and NQI method (FQINQI) was 0.382-0.590 and 0.106-0.245, respectively, and a positive relationship between FQIIQI and FQINQI was observed.

Conclusion

Our results highlight the great differences in mineral and juice characteristics among fruit parts, which mediated fruit quality. The strategy of fruit quality assessment using the FQI can be expanded for targeted utilization in the citrus industry.

Fruit waste: a current perspective for the sustainable production of pharmacological, nutraceutical, and bioactive resources

Fruits are crucial components of a balanced diet and a good source of natural antioxidants, that have proven efficacy in various chronic illnesses. Various kinds of waste generated from fruit industries are considered a global concern. By utilizing this fruit waste, the international goal of "zero waste" can be achieved by sustainable utilization of these waste materials as a rich source of secondary metabolites. Moreover, to overcome this waste burden, research have focused on recovering the bioactive compounds from fruit industries and obtaining a new strategy to combat certain chronic diseases. The separation of high-value substances from fruit waste, including phytochemicals, dietary fibers, and polysaccharides which can then be used as functional ingredients for long-term health benefits. Several novel extraction technologies like ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and supercritical fluid extraction (SFE) could provide an alternative approach for successful extraction of the valuable bioactives from the fruit waste for their utilization as nutraceuticals, therapeutics, and value-added products. Most of these waste-derived secondary metabolites comprise polyphenols, which have been reported to have anti-inflammatory, insulin resistance-treating, cardiovascular disease-maintaining, probiotics-enhancing, or even anti-microbial and anti-viral capabilities. This review summarizes the current knowledge of fruit waste by-products in pharmacological, biological, and probiotic applications and highlights several methods for identifying efficacious bioactive compounds from fruit wastes.

Roles of citrus fruits on energy expenditure, body weight management, and metabolic biomarkers: a comprehensive review

Citrus fruits are widely consumed for their nutritional and health benefits. They belong to the Rutaceae and have many varieties, such as sweet orange (Citrus sinensis), which is the most popular. Citrus fruits are rich in water (>80%), dietary fiber, and vitamins. They also contain bioactive components, which may modulate energy metabolism and lipid oxidation through various mechanisms. These mechanisms include stimulating β3-adrenergic receptors, increasing mitochondrial biogenesis and thermogenesis, activating AMP kinase and peroxisome proliferator-activated receptor-gamma coactivator-1α pathways, inhibiting lipogenesis and lipid accumulation, and inducing browning of white adipose tissue. This review summarizes the mechanisms and outcomes of citrus fruits and their metabolites on energy metabolism and body weight in different experimental models. The literature was searched for in vitro and in vivo animal and human studies that investigated the effects of citrus consumption on energy expenditure, thermogenesis, adipogenesis, and lipid accumulation. Citrus fruits and their metabolites have shown promising effects on energy metabolism and lipid oxidation in in vitro and in vivo animal studies. However, the evidence from human studies is limited and inconsistent. Possible reasons for the discrepancy are briefly discussed, and knowledge gaps and research needs are identified for future studies. Citrus fruits may have beneficial effects on energy metabolism and body weight, but more rigorous and well-designed human trials are needed to confirm their efficacy and safety.

Bioactive Components and Their Activities from Different Parts of Citrus aurantifolia (Christm.) Swingle for Food Development

Citrus aurantifolia is part of the Rutaceae family and belongs to the genus Citrus. It is widely used in food, the chemical industry, and pharmaceuticals because it has a unique flavor and odor. It is nutrient-rich and is beneficial as an antibacterial, anticancer, antioxidant, anti-inflammatory, and insecticide. Secondary metabolites present in C. aurantifolia are what give rise to biological action. Flavonoids, terpenoids, phenolics, limonoids, alkaloids, and essential oils are among the secondary metabolites/phytochemicals discovered in C. aurantifolia. Every portion of the plant's C. aurantifolia has a different composition of secondary metabolites. Environmental conditions such as light and temperature affect the oxidative stability of the secondary metabolites from C. aurantifolia. The oxidative stability has been increased by using microencapsulation. The advantages of microencapsulation are control of the release, solubilization, and protection of the bioactive component. Therefore, the chemical makeup and biological functions of the various plant components of C. aurantifolia must be investigated. The aim of this review is to discuss the bioactive components of C. aurantifolia such as essential oils, flavonoids, terpenoids, phenolic, limonoids, and alkaloids obtained from different parts of the plants and their biological activities such as being antibacterial, antioxidant, anticancer, an insecticide, and anti-inflammatory. In addition, various extraction techniques of the compounds out of different parts of the plant matrix as well as the microencapsulation of the bioactive components in food are also provided.

Effect of Thyme (Thymus vulgaris L.) Used in Diets with Extruded Flaxseed on the Antioxidant and Lipid Profile of the Blood and Tissues of Fattening Pigs

Thyme has strong antioxidant properties and, therefore, can reduce the intensity of oxidative processes taking place in the body. The study aimed to assess whether the addition of thyme to diets for fattening pigs containing extruded flaxseeds, a source of n-3 PUFAs, which are particularly susceptible to oxidation, would have a positive effect on redox status and lipid metabolism. The experiment was conducted using 120 weaners (WBP × Neckar crosses) of about 30 kg BW, which were kept until the end of fattening (about 110 kg BW) and divided into three groups of 40 pigs. The control group received a diet with 4% extruded flaxseed. In groups T1 and T3, 1% or 3% of thyme was added to the basal diet. The introduction of 3% thyme resulted in a decrease in the total cholesterol level in the blood and the loin muscle. Moreover, an increase in SOD and CAT activity and a decrease in FRAP and LOOH was noted. Following supplementation with 3% thyme, the n-3 PUFA content and n-3/n-6 ratio increased, while the SFA content was significantly reduced. The results of the studies indicate that thyme has a positive effect on the redox status and lipid profile of the blood and muscles.

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.

Cadmium, lead, mercury, and arsenic in fresh fruits and fruit products intended for human consumption in the Republic of Serbia, 2015-2017

The European Commission has established legislation for toxic metals in certain foodstuffs in order to protect public health already in 1993. After several amendments, new maximum levels for cadmium and lead in certain foods were set as per 30 and 31 August 2021 for lead and cadmium, respectively. The new Serbian Regulation on "maximum levels of certain contaminants in food" is fully harmonised with this European legislation. The concentrations of cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) were determined in 832 samples of 39 species of fruits and processed fruits, collected during the period January 2015 to December 2017. Fruits and fruit products originated from 45 countries, including Serbia. Samples were analysed by inductively coupled plasma - optical emission spectrometry (ICP-OES). Concentrations of cadmium, lead, mercury, and arsenic in fruits and fruit products were compared to these maximum levels (MLs). Overall, measurable Cd, Pb, Hg, and As were found in 377 samples (45.3%). According to the former regulations, the maximum levels of Cd and Pb for analysed fruits and fruit products were exceeded in only 10 samples (1.20%; n = 832): Cd in 6 and Pb in 4 samples, but according to the latest regulations, the maximum levels of Cd and Pb for fruits were exceeded in 196 of the samples (23.9%; n = 820): Cd in 191 and Pb in 5 samples. The increase of ML exceedances shows that attention needs to be paid for compliance of food to the recent MLs for these metals.

Nutritional value and antioxidant capacity of organic and conventional vegetables of the genus Allium

There are indications that organically grown plants are safer for health and have higher antioxidant content than conventional ones. Vegetables of the genus Allium L. are a valuable source of health-promoting substances, including compounds with antioxidant properties. The aim of the study was to compare the antioxidant potential and nutritional value of four species of Allium L. vegetables obtained from organic and conventional production: garlic, leek and red and yellow onion. Their proximate and mineral composition were determined, as well as the content of bioactive substances and antioxidant potential. The study showed that the cultivation method significantly influenced the parameters tested. Comparison of organic vegetables with conventional ones in terms of content of dry matter, crude protein and crude fibre revealed no general trend indicating the superiority of one method over the other. However, all organic vegetables analysed were more abundant in minerals (Ca, Mg, Fe, Zn, Cu and Mn) and bioactive compounds. They also exhibited higher antioxidant capacity as measured by the FRAP and DPPH^. tests. Their consumption (especially organic garlic and leek) may therefore strengthen the body's natural antioxidant defences and is beneficial for health.

Value-Added Utilization of Citrus Peels in Improving Functional Properties and Probiotic Viability of Acidophilus-bifidus-thermophilus (ABT)-Type Synbiotic Yoghurt during Cold Storage

Citrus peel, a fruit-processing waste, is a substantial source of naturally occurring health-promoting compounds, including polyphenols, and has great potential as a dietary supplement for enhancing the functional properties of food. The present work aimed to investigate the effects of sour orange (SO), sweet orange (SWO), and lemon (LO) peels on the typical physiochemical, antioxidant, antibacterial, and probiotic properties of synbiotic yoghurt fermented by acidophilus-bifidus-thermophilus (ABT)-type cultures during cold storage (0−28 days). High-performance liquid chromatography-diode array detection (HPLC-DAD) analysis showed that the total phenolic content in the SO peel were more than 2-fold higher than that in the SWO and LO peel. The predominant phenolic compounds were myricetin (2.10 mg/g dry weight) and o-coumaric acid (1.13 mg/g) in SO peel, benzoic acid (0.81 mg/g) and naringin (0.72 mg/g) in SWO peel, and benzoic acid (0.76 mg/g) and quercetin (0.36 mg/g) in LO peel. Only 0.5% (w/w) of citrus peel addition did not reduce the overall acceptance of ABT synbiotic yoghurt but led to increased acidity and decreased moisture during cold storage (14 and 28 days). Additionally, compared to control samples without citrus peel addition, supplementation with citrus peels improved the antioxidant property of the ABT synbiotic yoghurt. ABT milks with SO and SWO peel addition had significantly stronger DPPH radical scavenging activities than that with LO peel addition (p < 0.05). Antibacterial analysis of ABT synbiotic yoghurt with citrus peel addition showed that the diameters of inhibition zones against S. aureus, B. subtilis, and E. coli increased by 0.6−1.9 mm relative to the control groups, suggesting the enhancement of antibacterial activities by citrus peels. The viabilities of probiotic starter cultures (L. acidophilus, S. thermophilus, and Bifidobacterial sp.) were also enhanced by the incorporation of citrus peels in synbiotic yoghurt during cold storage. Hence, our results suggest that citrus peels, especially SO and SWO peels, could be recommended as a promising multifunctional additive for the development of probiotic and synbiotic yoghurt with enhanced antioxidant and antibacterial properties, as well as probiotic viability.

Insights on the Extraction and Analysis of Phenolic Compounds from Citrus Fruits: Green Perspectives and Current Status

Citrus fruits (CF) are highly consumed worldwide, fresh, processed, or prepared as juices and pies. To illustrate the high economic importance of CF, the global production of these commodities in 2021 was around 98 million tons. CF's composition is considered an excellent source of phenolic compounds (PC) as they have a large amount and variety. Since ancient times, PC has been highlighted to promote several benefits related to oxidative stress disorders, such as chronic diseases and cancer. Recent studies suggest that consuming citrus fruits can prevent some of these diseases. However, due to the complexity of citrus matrices, extracting compounds of interest from these types of samples, and identifying and quantifying them effectively, is not a simple task. In this context, several extractive and analytical proposals have been used. This review discusses current research involving CF, focusing mainly on PC extraction and analysis methods, regarding advantages and disadvantages from the perspective of Green Chemistry.

Physico-Chemical Attributes of Lemon Fruits as Affected by Growing Substrate and Rootstock

Due to its high content of bioactive compounds, the lemon is considered one of the most relevant species around the world. Its great economic importance is motivated, in addition to its fresh consumption, by its applications in the medical, pharmaceutical, and food industries, etc. However, the chemical and nutritional composition of lemon is not constant and can be influenced by external factors such as variety, weather conditions, crop management, etc. Determining the compositional variations of the fruit, essential to defining its potential use, was the main objective of this study. The physicochemical characteristics of the ‘Verna’ lemon were studied as a function of two controlled variables, the growing substrate and the rootstock. For this, 90 lemon trees were cultivated in three rootstocks and three different culture media. Lemon trees cultivated with 50% sediment/peat mix substrate presented a higher total production (590 lemons and 90.53 kg) while this production was 80% lower on trees cultivated with 75% marine sediment. Citrus macrophylla and Citrus aurantium/Citrus sinensis rootstocks showed a significantly higher production than the Citrus aurantium. All the fruits presented a predominantly yellow color appropriate for the market (0 < CI < +5). Nutritional and chemical parameters were consistent with data reported for the ‘Verna’ clones. All the obtained lemons were suitable for marketing and consumption both in fresh and processed forms. The results indicated the limited influence that the studied variables have on the quality parameters of lemon fruits, but they also could confirm the potential of marine sediment as a culture substrate.

Fruit Juice Industry Wastes as a Source of Bioactives

Food processing sustainability, as well as waste minimization, are key concerns for the modern food industry. A significant amount of waste is generated by the fruit juice industry each year. In addition to the economic losses caused by the removal of these wastes, its impact on the environment is undeniable. Therefore, researchers have focused on recovering the bioactive components from fruit juice processing, in which a great number of phytochemicals still exist in the agro-industrial wastes, to help minimize the waste burden as well as provide new sources of bioactive compounds, which are believed to be protective agents against certain diseases such as cardiovascular diseases, cancer, and diabetes. Although these wastes contain non-negligible amounts of bioactive compounds, information on the utilization of these byproducts in functional ingredient/food production and their impact on the sensory quality of food products is still scarce. In this regard, this review summarizes the most recent literature on bioactive compounds present in the wastes of apple, citrus fruits, berries, stoned fruits, melons, and tropical fruit juices, together with their extraction techniques and valorization approaches. Besides, on the one hand, examples of different current food applications with the use of these wastes are provided. On the other hand, the challenges with respect to economic, sensory, and safety issues are also discussed.

Total phenolics, flavonoids, and antioxidant activity of agricultural wastes, and their ability to remove some pesticide residues

Organophosphorus pesticides (OPPs) cause great risk to human health as they are used globally. Therefore, the purpose of this research was to determine the total phenolics, flavonoids, and antioxidant activity of agricultural waste, as well as to control the pesticide residues (diazinon, and parathion) at a laboratory scale level using dried-milled fruit wastes. The pesticide residues parathion and diazinon were used at concentrations of 0.094, and 1.90 mg/mL respectively. The fruit wastes used in this study were orange and banana peels, as well as date stones, and they were used in two concentrations (3 and 9 g/30 mL deionized water). The total phenolic and flavonoid contents and the antioxidant activity were measured in fruit wastes. Also, the Fourier transmitted infrared (FTIR) spectra of fruit wastes were established to figure out the nature of the functional groups found before and after pesticide residues removal. The ability of fruit wastes to remove pesticides residues was determined using Gas Chromatography/Mass spectrometry (GC/MS). Data showed that date stones contained a higher amount of total phenolic content than orange and banana peels. However, orange peels contained a higher amount of total flavonoid contents than those of date stones and banana peels. As for antioxidant activity, banana peels recorded the higher antioxidant activity, followed by orange peels and date stones respectively. Results revealed that there was no relation between total phenolic content, total flavonoid content, and antioxidant activity. Results also indicated that date stones at a concentration of 9 g successfully reduced diazinon (81.18%), followed by banana (63.86%) and orange peels (43.42%) respectively, whereas parathion was reduced by banana peels at a concentration of 9 g (50.34%), followed by orange peels (45.28%), and date stones (39.52%) respectively. This study demonstrated that agricultural wastes were effective in the adsorption of diazinon from water, and their use is considered safe for the environment.

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Date stones successfully reduced diazinon by 81.18%, whereas banana peels effectively reduced parathion by 50.34%.

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FTIR spectra of fruit wastes displaced severeal peaks.

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Date stones contained a higher amount of total phenolic content.

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Orange peels contained a higher amount of total flavonoid contents.

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Banana peels recorded the higher antioxidant activity.

Multievaluation Strategy for Liujunzi Decoction: Fingerprint Characterization, Chemometrics Analysis, Network Pharmacology, and Molecular Docking

Liujunzi decoction (LJZD), a traditional tonic formula for treating “qi” deficiency of the spleen and the syndrome of phlegm dampness, can be used to prevent and treat chemotherapy-induced anorexia (CIA). The chemical constituents of LJZD are rather complex; therefore, it is of great significance to establish an effective and economic quality control method to ensure the quality consistency and stability of LJZD. With one chromatographic condition, 13 common peaks detected at 203 nm were selected to establish a fingerprint similarity model and 7 chemical constituents were identified as ephedrine hydrochloride, liquiritin, hesperidin, ginsenoside Rg1, jujuboside A, 6-gingerol, and atractylenolide III. Ten batches of LJZD were divided into two groups by cluster analysis and principal component analysis (PCA), and four main components (ephedrine hydrochloride, hesperidin, ginsenoside Rg1, and jujuboside A) of LJZD were analyzed. Also, the analysis results were combined with network pharmacology and molecular docking technology to further predict how LJZD could prevent and treat CIA. We found that these four main components of LJZD spontaneously combined with four CIA targets (SRC, PIK3R1, MAPK1, and AKT1). In this study, we established the fingerprint of LJZD for the first time, and through a comprehensive multiassessment method, we also successively analyzed the fingerprint and chemometrics.

Antioxidant and Antibacterial Effect of Fruit Peel Powders in Chicken Patties

Meat industries are eager to find natural low-cost additives for improving the health benefits and shelf life of meat products. The present study elucidated the effect of four different fruit peel powders, namely lemon, orange, grapefruit, and banana (1% each), on the oxidative stability, microbial quality, physicochemical properties, and sensory attributes of chicken patties during 3 months of storage at −18 °C. The total phenolics and flavonoids as well as the antioxidant activity of the fruit peel powders were analyzed. The lemon peel powder contained the highest bioactive substance (90.5 mg gallic acid/g total phenolics and 35 mg rutin/g total flavonoids) and had the highest free radical scavenging activity (90%). The fruit peel powders used, especially the banana peel powder, induced an increase in protein (22.18 g/100 g) and a decrease in fat (10.52 g/100 g) content. Furthermore, all the fruit peel powders exhibited significant antioxidant and antibacterial activities compared with the control samples. The sensory attributes were improved in all treated groups, especially in the lemon peel powder-treated patties. Consequently, the obtained results support the application of fruit peel powders, as natural sources of antioxidants with antibacterial effects, as health-promoting functional additives during the manufacturing of meat products.

Effect of Ultrasound-Assisted Pretreatment on Extraction Efficiency of Essential Oil and Bioactive Compounds from Citrus Waste By-Products

Waste or by-product use is in focus for reducing the environmental threat and acquiring wealth out of waste. The current study aim was to investigate the effects of ultrasound pretreatment on the extraction of bioactive compounds and composition of essential oils extracted from citrus waste. The response surface methodology (RSM) was used to optimize higher yield extraction parameters. Pretreatment of ultrasound-assisted extraction recovered 33% enhanced yield with reduced time and was economical as compared to conventional hydro-distilled process. The functional quality of essential oil was determined using FTIR and GC-MS. Antioxidants from citrus peel and pulp/pomace were extracted and analyzed by spectroscopic techniques. The quantification of bioactive compounds from citrus waste was performed using high performance liquid chromatography (HPLC). Mass transfer rate of antioxidants from peel and pomace were 30% increased as a result of ultrasound-assisted treatment. The significantly (p ≤ 0.05) higher TPC (735.54 mg/100 g) and antioxidant activity (44.26%) was recorded in Citrus sinensis Pulp and peel respectively. The bioactive compounds such as hesperidin (31.52 mg/100 g) was significantly higher in (p ≤ 0.05) in Citrus sinensis pulnd extract. Vanillin was found 1.21 mg/100 g in peel extract of citrus fruit, moreover vanillin was not detected in pulp extract. Myrecitin was not detected in both the samples. The bioactive natural compounds extracted from citrus peel can be used in food and pharma sector as natural anti-oxidantcompounds.

Pressurized Extraction as an Opportunity to Recover Antioxidants from Orange Peels: Heat treatment and Nanoemulsion Design for Modulating Oxidative Stress

Orange peel by-products generated in the food industry are an important source of value-added compounds that can be potentially reused. In the current research, the effect of oven-drying (50–70 °C) and freeze-drying on the bioactive compounds and antioxidant potential from Navelina, Salustriana, and Sanguina peel waste was investigated using pressurized extraction (ASE). Sixty volatile components were identified by ASE-GC-MS. The levels of terpene derivatives (sesquitenenes, alcohols, aldehydes, hydrocarbons, and esters) remained practically unaffected among fresh and freeze-dried orange peels, whereas drying at 70 °C caused significative decreases in Navelina, Salustriana, and Sanguina peels. Hesperidin and narirutin were the main flavonoids quantified by HPLC-MS. Freeze-dried Sanguina peels showed the highest levels of total-polyphenols (113.3 mg GAE·g⁻¹), total flavonoids (39.0 mg QE·g⁻¹), outstanding values of hesperedin (187.6 µg·g⁻¹), phenol acids (16.54 mg·g⁻¹ DW), and the greatest antioxidant values (DPPH•, FRAP, and ABTS^•+ assays) in comparison with oven-dried samples and the other varieties. Nanotechnology approaches allowed the formulation of antioxidant-loaded nanoemulsions, stabilized with lecithin, starting from orange peel extracts. Those provided 70–80% of protection against oxidative UV-radiation, also decreasing the ROS levels into the Caco-2 cells. Overall, pressurized extracts from freeze-drying orange peel can be considered a good source of natural antioxidants that could be exploited in food applications for the development of new products of commercial interest.

A review of chemical constituents and health-promoting effects of citrus peels

Citrus is one of the main fruits processed worldwide, producing a lot of industrial by-products. As the main part of citrus "residue", citrus peels have a wide application prospect. They could not only be directly used to produce various food products, but also be used as promising biofuels to produce ethanol and methane. Additionally, functional components (flavonoids, limonoids, alkaloids, essential oils and pectin) extracted from citrus peels have been related to the improvement of human health against active oxygen, inflammatory, cancer and metabolic disorders. Therefore, it is clear that the citrus peels have great potential to be developed into useful functional foods, medicines and biofuels. This review systematically summarizes the recent advances in current uses, processing, bioactive components and biological properties of citrus peels. A better understanding of citrus peels may provide reference for making full use of it.

A Transcriptional Analysis of the Genes Involved in the Ascorbic Acid Pathways Based on a Comparison of the Juice and Leaves of Navel and Anthocyanin-Rich Sweet Orange Varieties

Sweet oranges are an important source of ascorbic acid (AsA). In this study, the content of AsA in the juice and leaves of four orange clonal selections, different in terms of maturity time and the presence/absence of anthocyanins, was correlated with the transcription levels of the main genes involved in the biosynthesis, recycling, and degradation pathways. Within each variety, differences in the above pathways and the AsA amount were found between the analysed tissues. Variations were also observed at different stages of fruit development and maturation. At the beginning of fruit development, AsA accumulation was attributable to the synergic action of l-galactose and Myo-inositol, while the l-gulose pathway was predominant between the end of fruit development and the beginning of ripening. In leaves, the l-galactose pathway appeared to play a major role in AsA accumulation, even though higher GalUr isoform expression suggests a synergistic contribution of both pathways in this tissue. In juice, the trend of the AsA content may be related to the decrease in the transcription levels of the GME, GDH, MyoOx, and GalUr12 genes. Newhall was the genotype that accumulated the most AsA. The difference between Newhall and the other varieties seems to be attributable to the GLDH, GalUr12, APX2, and DHAR3 genes.