Polyphenols, ascorbic acid and antioxidant capacity of commercial nutritional drinks, fruit juices, smoothies and teas

A study on processing of dried acerola (Malpighia glabra l.) tea bag and its storage condition

This research investigated the effect of mixing formulas and storage conditions on the quality of the acerola tea bags. The tea bag formula, which includes 94 g of acerola fragments, 6 g of oolong tea, and 3 g of sweet leaves, had the best sensory quality. Under this condition, the acerola tea powder had vitamin C of 759.63 mg/100 g, phenolic content of 1747.26 mg GAE/100 g, and antioxidant activity of 3025.70 mg AAE/100 g. Furthermore, the present study found that the acerola tea's sorption isotherm curve was fitted with the GAB model (R2 = 0.97). In addition, this study also examined the effects of several storage temperatures, such as 7 ± 2 °C, room temperature, and 40 °C, on the stability of an acerola tea for up to 28 days. The degradation of vitamin C, polyphenols, and antioxidant activity in tea samples during storage was fitted with the Arrhenius plots, first-order reactions, and Ball equation. Furthermore, at whatever storage temperature, the tea's final water activity was not above the safe zone of below 0.6.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05931-3.

Smoothies Marketed in Spain: Are They Complying with Labeling Legislation?

There is no legal definition of a smoothie, so the European legislation applicable to its labeling is that of fruit juice. The smoothie market has grown in recent years, as it can include a wide variety of ingredients: fruits, fruit purees, honey, milk and vegetable milks, vegetables, herbs, cereals, cereal flours, seaweed, and crushed ice. In this study, 57 smoothies were reviewed. All of them were purchased in supermarkets and classified into eight types according to the main ingredients. Fifteen legal statements/items were reviewed on the pack labels: eleven mandatory and three optional. Moreover, nutrition labels, nutritional claims, images, marks, and other symbols were also reviewed. Only 22.8% of the samples complied with EU and Spanish labeling legislation. More incorrectness was related to the name of the food and the fruits included as main ingredients; other errors related to the allergy/intolerance statements, and some nutritional claims concerning vitamin C were also detected to a lesser extent. General advice is provided for consumers to interpret smoothie labels correctly. Lawmakers should amend legislation to accept the term "smoothie" as a legal name.

Effect of Tomato, Beetroot and Carrot Juice Addition on Physicochemical, Antioxidant and Texture Properties of Wheat Bread

Bakery products, including bread, are important components of the diet of people all over the world. One of the food industry's goals is to improve its quality in the context of healthiness and physical parameters. Consumers' perception of sensory quality is an important aspect of food choice. Thus, the study aimed to enhance nutritional parameters (antioxidant capacity, content of phenolic compounds) together with maintaining or increasing bread quality (texture, color, volume and sensory properties). Among vegetable juices, tomato, beetroot and carrot were selected, as they are easily accessible in Europe and are inexpensive. At the same time, those juices are known to be high in antioxidants. In this study, the effect of substituting recipe water with tomato, beetroot and carrot juices (replacement level: 15, 30, 50% v/v) was evaluated in terms of the specific volume, texture, color, acidity, polyphenol contents, antioxidant and sensory properties. It was concluded that juice content had a significant positive impact on physicochemical parameters such as volume, color, acidity, as well as the antioxidant activity of breads. The carrot and beetroot juices were the most efficient in terms of shaping wheat bread properties, especially in terms of antioxidant activity.

Characterizations of Six Pomegranate (Punica granatum L.) Varieties of Global Commercial Interest in Morocco: Pomological, Organoleptic, Chemical and Biochemical Studies

Pomegranate variety properties are important not only to demonstrate their diversity but also to satisfy the current market need for high-quality fruits. This study aims to characterize pomological and physico-chemical features as well as the antioxidant capacity of Moroccan local cultivars (Djeibi, Mersi, Sefri 1 and Sefri 2) compared to the imported ones (Mollar de Elche and Hicaz). The pomological characteristics of varieties were relatively diverse. The juice varieties (PJ) displayed a marketed variability in organoleptic and quality properties, such as the flavor, juice yield, and micro/macronutrients contents. Interrelationships among the analyzed properties and PJ varieties were investigated by principal component analysis (PCA). Dimension of the data set was reduced to two components by PCA accounting for 64.53% of the variability observed. The rinds varieties (PR) were studied for their total phenolics, flavonoids, and condensed tannins quantifications. PR varieties extracts exhibited different levels of free radical scavenging activity and local varieties revealed a greater potential with stability over time. The HPLC-DAD analyses of PR extracts revealed (+) catechin as the major compound, where the highest content was found for the local varieties. The SEC analysis showed the molecular weight distribution of phenolic compounds with a high size of condensed tannins formed by the polymerization of the catechin monomer. Given these properties, this research provides an easy selection of high-quality fruits as potential candidates for local market needs.

The Effects of Bioactive Compounds from Blueberry and Blackcurrant Powder on Oat Bran Pastes: Enhancing In Vitro Antioxidant Activity and Reducing Reactive Oxygen Species in Lipopolysaccharide-Stimulated Raw264.7 Macrophages

In this study, blueberry and blackcurrant powder were chosen as the phenolic-rich enrichments for oat bran. A Rapid Visco Analyser was used to form blueberry and blackcurrant enriched oat pastes. An in vitro digestion process evaluated the changes of phenolic compounds and the in vitro antioxidant potential of extracts of pastes. The anthocyanidin profiles in the extracts were characterised by the pH differential method. The results showed that blueberry and blackcurrant powder significantly increased the content of phenolic compounds and the in vitro antioxidant capacity of pastes, while the total flavonoid content decreased after digestion compared to the undigested samples. Strong correlations between these bioactive compounds and antioxidant values were observed. Lipopolysaccharide-stimulated RAW264.7 macrophages were used to investigate the intracellular antioxidant activity of the extracts from the digested oat bran paste with 25% enrichment of blueberry or blackcurrant powder. The results indicated that the extracts of digested pastes prevented the macrophages from experiencing lipopolysaccharide (LPS)-stimulated intracellular reactive oxygen species accumulation, mainly by the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signalling pathway. These findings suggest that the bioactive ingredients from blueberry and blackcurrant powder enhanced the in vitro and intracellular antioxidant capacity of oat bran pastes, and these enriched pastes have the potential to be utilised in the development of the functional foods.

Role of fruit juice in achieving the 5-a-day recommendation for fruit and vegetable intake

Although there is strong evidence that consumption of fruit and vegetables is associated with a reduced rate of all-cause mortality, only a minority of the population consumes 5 servings a day, and campaigns to increase intake have had limited success. This review examines whether encouraging the consumption of fruit juice might offer a step toward the 5-a-day target. Reasons given for not consuming whole fruit involve practicalities, inconvenience, and the effort required. Psychologically, what is important is not only basic information about health, but how individuals interpret their ability to implement that information. It has been argued that fruit juice avoids the problems that commonly prevent fruit consumption and thus provides a practical means of increasing intake and benefitting health through an approach with which the population can readily engage. Those arguing against consuming fruit juice emphasize that it is a source of sugar lacking fiber, yet juice provides nutrients such as vitamin C, carotenoids, and polyphenols that offer health-related benefits. Actively encouraging the daily consumption of fruit juice in public health policy could help populations achieve the 5-a-day recommendation for fruit and vegetable intake.

Functional Attributes and Anticancer Potentialities of Chico (Pachycereus Weberi) and Jiotilla (Escontria Chiotilla) Fruits Extract

Mexico has a great diversity of cacti, however, many of their fruits have not been studied in greater depth. Several bioactive compounds available in cacti juices extract have demonstrated nutraceutical properties. Two cactus species are interesting for their biologically active pigments, which are chico (Pachycereus weberi (J. M. Coult.) Backeb)) and jiotilla (Escontria chiotilla (Weber) Rose)). Hence, the goal of this work was to evaluate the bioactive compounds, i.e., betalains, total phenolic, vitamin C, antioxidant, and mineral content in the extract of the above-mentioned P. weberi and E. chiotilla. Then, clarified extracts were evaluated for their antioxidant activity and cytotoxicity (cancer cell lines) potentialities. Based on the obtained results, Chico fruit extract was found to be a good source of vitamin C (27.19 ± 1.95 mg L-Ascorbic acid/100 g fresh sample). Moreover, chico extract resulted in a high concentration of micronutrients, i.e., potassium (517.75 ± 16.78 mg/100 g) and zinc (2.46 ± 0.65 mg/100 g). On the other hand, Jiotilla has a high content of biologically active pigment, i.e., betaxanthins (4.17 ± 0.35 mg/g dry sample). The antioxidant activities of clarified extracts of chico and jiotilla were 80.01 ± 5.10 and 280.88 ± 7.62 mg/100 g fresh sample (DPPH method), respectively. From the cytotoxicity perspective against cancer cell lines, i.e., CaCo-2, MCF-7, HepG2, and PC-3, the clarified extracts of chico showed cytotoxicity (%cell viability) in CaCo-2 (49.7 ± 0.01%) and MCF-7 (45.56 ± 0.05%). A normal fibroblast cell line (NIH/3T3) was used, as a control, for comparison purposes. While jiotilla extract had cytotoxicity against HepG2 (47.31 ± 0.03%) and PC-3 (53.65 ± 0.04%). These results demonstrated that Chico and jiotilla are excellent resources of biologically active constituents with nutraceuticals potentialities.

Sugar-containing beverages and their association with risk of breast, endometrial, ovarian and colorectal cancers among Canadian women

BACKGROUND

The association of sugar containing beverages (SCBs) with risk of breast, endometrial, ovarian and colorectal cancers is unclear. Therefore, we investigated these associations in the Canadian Study of Diet, Lifestyle, and Health.

METHODS

The study population comprised an age-stratified subcohort of 3185 women and 848, 161, 91 and 243 breast, endometrial, ovarian and colorectal cancer cases, respectively. We used Cox proportional hazards regression models modified for the case-cohort design to assess the associations of SCBs with risk of the aforementioned cancers.

RESULTS

Compared to SCB intake in the lowest tertile, SCB intake in the highest tertile was positively associated with endometrial cancer risk (HR_{T3 vs T1} = 1.58, 95 % CI = 1.08-2.33 and 1.78, 95 % CI = 1.12-2.81 for overall and Type 1 endometrial cancer, respectively) and ovarian cancer (HR_{T3 vs T1} = 1.76, 95 % CI: 1.09-2.83). Fruit juice intake was also positively associated with risk of Type 1endometrial (HR_{T3 vs T1} = 1.63, 95 % CI = 1.03-2.60). After excluding women with diabetes or cardiovascular diseases, we also observed sugar-sweetened beverages (SSBs) intake in the highest tertile was associated with higher risk of Type 1 endometrial cancer (HR _{T3 vs T1} = 1.65; 95 % CI: 1.03-2.64). None of the beverages was associated with risk of breast or colorectal cancer.

CONCLUSION

We conclude that, in this cohort, relatively high SCB intake was associated with higher risk of endometrial and ovarian cancers, but not of breast or colorectal cancers. Our findings also suggest that relatively high SSB and fruit juice intake are associated with higher risk of Type 1 endometrial cancer.

Ascorbic acid, sucrose and olive oil lipids mitigate the inhibitory effects of pectin on the bioaccessibility and Caco-2 cellular uptake of ferulic acid and naringenin

Sucrose and olive oil successfully negate the inhibitory effect of pectin on the overall in vitro availability of ferulic acid and naringenin by substantially increasing the bioaccessibility and not cellular uptake of the phenolics.

A Micromethod for Polyphenol High-Throughput Screening Saves 90 Percent Reagents and Sample Volume

There is ample evidence that polyphenols are important natural substances with pronounced antioxidative properties. This study aimed to develop a fast and reliable method to determine total polyphenol content (TPC) in foodstuffs and human samples. The microtitration format offers the advantage of low sample volumes in the microlitre range, facilitating high-throughput screening with 40 samples simultaneously. We accordingly adjusted the so-called Folin–Ciocalteu method to a microtitre format (polyphenols microtitre—PPm) with 90% reduction of reagents. The assay was standardized with gallic acid in the range between 0.1 and 3 mM, using a 20 µL sample volume. The intra-assay coefficient of variation (CV) was less than 5%, and inter-assay CV was in the range of 10%. Wavelength was measured at 766 nm after two hours of incubation. This micromethod correlates significantly with both the classical Folin–Ciocalteu method and High-Performance Thin-Layer Chromatography (HPTLC) (r² = 0.9829). We further observed a significant correlation between PPm and total antioxidants (r² = 0.918). The highest polyphenol concentrations were obtained for red, blue, and black fruits, vegetables, and juices. Extracts of red grapes could be harvested almost sugar free and might serve as a basis for polyphenol supplementation. Beer, flour, and bread contained polyphenol concentrations sufficient to meet the minimal daily requirement. We conclude that PPm is a sensitive and reliable method that detects polyphenols even in samples diluted 10-fold. The literature strongly recommends further investigations on the effects of polyphenol uptake on human and animal health.

Characterization of Fulvic Acid Beverages by Mineral Profile and Antioxidant Capacity

The main purpose of the study was to investigate the quality of fulvic acid-based food products. The concentrations of Ca, K, Mg, Na, Cu, Fe, Mn, and Zn, and antioxidant capacities of fulvic acid concentrates and ready-to drink beverages available on the global market were determined. The concentrations of minerals were determined using microwave plasma-atomic emission spectrometry. Antioxidant capacity was expressed as total polyphenol (TP) and flavonoid (TF) contents, the trolox equivalent antioxidant capacity (TEAC) and ferric reducing ability of plasma (FRAP) values. The daily portion of eight out of 14 products realized 45–135% of recommended daily allowance (RDA) for Fe. One of ready-to-drink beverages was also a good source of Mg (about 40% of RDA), and another one of Mn (about 70% of RDA). The concentrations of TP and TF in ready-to-drink beverages varied from 6.5 to 187 µg/mL, whereas in concentrates, from 5886 to 19,844 µg/mL. Dietary supplements or food products with fulvic acids may be a good source of antioxidant polyphenolic compounds and some minerals.

Effect of cold-pressed and normal centrifugal juicing on quality attributes of fresh juices: do cold-pressed juices harbor a superior nutritional quality and antioxidant capacity?

Cold-pressed juices are claimed to contain higher levels of antioxidants and bioactive compounds compared to normally centrifuged ones. Herein, we evaluated the antioxidant capacity and the bioactive compound contents of some freshly prepared fruit juices, extracted by a cold-pressed juicer and compared them to those prepared by a normal centrifugal juicer. We observed no significant differences between cold-pressed and normal centrifugal juices in terms of the contents of bioactive compounds (ascorbic acid, total phenolic, and total carotenoid) and antioxidant capacity (ferric ion reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity). Storage at room temperature (∼28 °C) adversely affected the ascorbic acid, total phenolics, total carotenoids, FRAP and DPPH values of the cold-pressed juices within 48 h. However, under simulated home-refrigerated storage conditions, the antioxidant capacity, contents of bioactive compounds and physicochemical properties of the cold-pressed juices remained unchanged till day 5 post-storage. However, at day 6, most of the parameters exhibited a decreasing trend and reached their lowest values at day 7. Principal component analysis confirmed significant changes in the quality of juices at day 7 of storage related to the first two principal components (ascorbic acid and FRAP). Our results strongly question the claim regarding the superior quality of cold-pressed juices. Moreover, our findings provided compelling evidence regarding the possible adverse effects of long storage under home-refrigerated conditions on the quality of cold-pressed juices.

Fruit-based juices: Focus on antioxidant properties-Study approach and update

This paper proposes a perspective literature review of the antioxidant properties in fruit-based juices. The total antioxidant properties due to compounds such as carotenoids, polyphenolic compounds, flavonoids, and tannins as well as the assessment of interactions between natural active compounds and other food matrix components can be seen as the first step in the study of potential health benefits of fruit-based juices. A brief summary is given on the significance of antioxidant properties of fruit juices, the conventional methods for antioxidant activity evaluation, and on the newly emerged sample analysis and data interpretation strategies, that is, chemometric analysis based on spectroscopic data. The effect of fruit processing techniques and the addition of ingredients on the antioxidant properties of fruit-based juices are also discussed.

A Critical Overview of Labeling Information of Pomegranate Juice-Based Drinks: Phytochemicals Content and Health Claims

Punicalagin is responsible for over 50% of the antioxidant activity of pomegranate, but ellagic acid (EA) and total polyphenol content (TPC) are also key parameters regarding pomegranate bioactivity. Many juices and other drinks based on pomegranate take advantage from the widespread healthy image of this fruit, whereas their real content of bioactive phytochemicals is low. For that reason, the objective of this study was to compare the labelling information with the real phytochemical contents (TPC, punicalagin [Pn] [isomers α, β], and EA). Titratable acidity (TA), color density (CD), polymeric color (PC), and sensory profiles (trained panel) were assessed. The experimental ranges of TPC and Pn contents were 2.75 to 70.9 mg/g and traces to 3.18 mg/g, respectively. The percentage of pomegranate juice was highly correlated with the intensity of the pomegranate ID attribute (R = 0.85; p < 0.001), Pn content (R = 0.71; p < 0.001), and EA content (R = 0.36; p < 0.001). The experimental results showed a high variability in the content of bioactive compounds and the need to urge food companies to optimize processes and storage conditions. Although no health claim for pomegranate has been authorized so far at the European Union, significant mismatches among labelling and bioactive compounds content are misleading consumers. PRACTICAL APPLICATION: Pomegranate juice and nectar producers need to evaluate the real content of bioactive Pn, EA, and TPC in their products to optimize formulation, heat treatment, packaging and storage conditions to guarantee high levels of bioactive compounds during shelf life. Producers' organizations may benefit from harmonizing Pom products labelling, so they may fulfill consumer expectations and may be ready if health claims are finally authorized for these products. The development of a new sensory quality marker will be an interesting option.

Use of a Potential Probiotic, Lactobacillus casei L4, in the Preparation of Fermented Coconut Water Beverage

Coconut water (CW) is a clear, nutritive liquid found as the coconut endosperm of green coconuts such as Cocos nucifera L., and its widespread consumption owes to its unique composition of sugars, minerals, vitamins, enzymes, and hormones. Probiotic fermentation of CW may facilitate the development of an improved functional beverage with probiotic benefits; therefore, we aimed to produce a fermented CW beverage using the potential probiotic Lactobacillus casei L4. CW was fermented with L. casei L4 for 48 h at 35°C, and the pH, organic acid-production rate, antioxidant activity, antibacterial activity, sugar, mineral, vitamin B12 levels, and total viable bacteria counts were investigated at 24 and 48 h. We demonstrated that the fermentation of CW with probiotic lactobacilli increased the cell viability count. Vitamin B12 production was highest in the extracellular environment at 48 h (11.47 μg/mL), while the total phenolic content was significantly (p < 0.05) higher in the fermented CW at 48 h (72.1 μg/mL gallic acid equivalents) than observed with the other investigated groups or time points. The fermented materials exhibited the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activities at 48 h (58.4 and 69.2%, respectively). The levels of most minerals remained unchanged in the fermented CW, except for calcium, manganese, phosphorus, and sodium. Furthermore, the culture supernatant from fermented CW inhibited the growth of foodborne pathogens such as Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, and Salmonella typhi, although the degree of inhibition varied between the species. Moreover, adding 15% honey and artificial coconut flavor to the fermented CW resulted in a better-tasting product, as demonstrated by a sensory-evaluation test. The obtained results indicated that the CW product fermented by L. casei L4 may be used as a novel functional beverage containing both electrolytes and probiotics, and can serve as a good vehicle for preparing a wider range of novel products.

Sensory Quality, Physicochemical Attributes, Polyphenol Profiles, and Residual Fungicides in Strawberries from Different Disease-Control Treatments

Using alternative agricultural practices in combination with proper postharvest handling has become a major goal to improve fresh produce quality. Here, two different strawberry ( Fragaria × ananassa) genotypes were used as a model to study the impact of repeated, reduced-fungicide or no-fungicide applications on the sensory quality, physicochemical attributes, polyphenol profiles, and residual fungicide in strawberries. Strawberries grown under reduced-fungicide applications had similar or better physicochemical quality than conventionally and organically grown fruit and lower levels of fungicide residues than conventional fruit. Overall, flavor- and health-related attributes of strawberries from reduced-fungicide applications were intermediate between conventional and organic fruit. Thus, growing strawberries with reduced-fungicide applications can be an alternative to conventional or organic agricultural practices.