Commercial Plant-Based Functional Beverages: A Comparative Study of Nutritional Composition and Bioactive Compounds

Abstract

Plant-based beverages, commonly referred to as functional beverages, have the potential to improve health since they contain bioactive components. A study was conducted to analyze the nutritional and bioactive profiles of functional beverages marketed in the United States and Peru, based on the different ingredients utilized. The determination of the nutritional content and bioactive compounds was carried out according to validated methods. The antioxidant activity of the beverages was assessed according to the DPPH and FRAP assays. The results showed that the beverages have a low caloric contribution, while they were characterized by a high content of bioactive compounds such as polyphenols, anthocyanins, carotenoids, and Vitamin C, associated with strong antioxidant activity. Significant differences were also found between the samples tested according to the ingredients used in the beverages. In conclusion, this research indicates that the plant beverages under investigation could potentially provide a noteworthy quantity of bioactive compounds linked to the various constituent types, hence catering to consumer preferences.

1. Introduction

At the current time, there is an increased demand for foods with beneficial properties beyond the provision of energy and nutrients, which are also known as health properties [1,2] and are mainly provided by biologically active components. Day-to-day life, and the ever-increasing demand for time away from home, means that consumers are turning to convenience foods that are “ready to eat” to provide these bioactive compounds. The most sought-after foods are those that are easy to access, transport, and consume, as well as those that offer a functional advantage. Beverages are the most popular. These beverages satisfy a physiological need, but also satisfy the desire of consumers to obtain healthier, more natural, refreshing, stimulating and nutritious options [3,4]. The global market of functional beverages has been growing, reaching approximately USD 9.8 billion in 2017; this is expected to grow to USD 19.7 billion by 2023 [5]. Also, according to the consumption preferences of a diverse population, food and drinks are the main sources of polyphenols (99.8%), with the remainder coming from supplements [6].

A functional beverage is considered to be a non-alcoholic beverage that provides additional health benefits through the inclusion of a bioactive ingredient from a plant, animal, marine, or micro-organism source [7], and their beneficial effects should be obtained by consuming normal amounts of the beverage as a part of the “normal” diet [2]. There are three general categories: dairy-based drinks, vegetable and fruit drinks, and sports or energy drinks [7,8].

Fruits and other vegetables are the preferred source of bioactive compounds with beneficial health effects for the prevention and/or treatment of diseases [9]. One of the main recommendations made by the scientific community is to consume plenty of fruit and vegetables and their products to provide a sufficient combination of bioactive compounds that are good for health. Most of the consumed products are beverages made with plant ingredients that are rich in bioactive compounds such as polyphenols, carotenoids, unsaturated fatty acids, probiotics, peptides, minerals, and vitamins [10]. Thus, the ingredients used in the beverages, such as fruits and some vegetables, provide the formulations with different micronutrients and a variety of bioactive compounds, which provide the antioxidant and chemopreventive power of the beverages [11]. Some studies evidence the association between functional beverages and a reduction in the risk of chronic diseases [12] and some types of cancer [13], as well as their ability to boost the immune system [14]. The incorporation of native Peruvian fruits is also gaining interest due to the attractive content of bioactive compounds and the associated antioxidant and protective health benefits, such as their antiproliferative and immunomodulatory activities [15].

In Peru, the export of fruits and other vegetables is growing and, therefore, interest in the consumption of native species has also been increasing. On the other hand, the United States market offers a wide variety of functional beverages, inspiring the plant-based beverages market in Peru as well as consumers interested in such “easy-to-drink” products. Therefore, this study covers the nutritional aspects of the ‘healthy’ and functional plant-based beverages available in the United States and Peru. An analysis is carried out to characterize the nutritional content and profile of some bioactive compounds, as well as their antioxidant activity, by in vitro assays.

2. Materials and Methods

2.1. Beverages Samples and Extraction Procedure

Different beverages were obtained from supermarkets in the United States and Peru, respectively, and were coded for use in the laboratory (

Table 1. Ingredients of functional beverages from the United States and Peruvian markets.

Sample Origin	Code	Ingredientes
		Fruits Pulp/Juice	Vegetables/Spices	Medicinal/Aromatic Plants	Bioactive Compounds Isolate	Bacteria Strains
United States	BVRG1	Passion fruit juice *, pineapple juice *, lime juice *.	Ginger juice *, habanero chili juice *.		zinc gluconate
	BVRG2	Pitaya purée *, pineapple juice *, lime juice *, elderberry juice concentrate *, elderberry extract powder *.	Ginger juice *	Aloe vera juice *
	BVRG3	Orange juice *, pineapple juice *, sea buckthorn juice *, lemon juice *.		Baobab powder *	Vegan Omega 3 from seaweed, colecalciferol (vitamin D3).	Bacillus coagulans GBI-30 6086
	BVRG4	Apple juice *, apple cider vinegar *, coconut water *, lemon juice *, ginger juice *.		Aloe vera juice *		Bacillus coagulans GBI-30 6086.
	BVRG5	Orange juice *, pineapple juice *, sea buckthorn juice *, lime juice *.		Baobab powder *
	BVRG6	Pineapple juice *, lemon juice *.	Acerola juice *, ginger juice *, cordyceps mushroom powder *.	Astragalus powder *
	BVRG7	Coconut water *, lime juice *.	Ginger juice *, cayenne pepper *.
	BVRG8	Camu camu *, raspberry *, lemon *, green apple *.	Ginger *
	BVRG9	Lemon *, green apple *.	Turmeric *, black pepper *
	BVRG10	Strawberry *, lemon *, green apple *.		Maple syrup *	Natural caffeine from green coffee beans, L-theanine, vitamin B12, structured reverse osmosis super water.
	BVRG11	Lemon *, green apple *.	Ginger *, cayenne pepper *.
	BVRG12	Pineapple, lemon.	Turmeric, carrot, ginger, black pepper.
	BVRG13	Orange juice *.	ginger juice *, cayenne pepper *.	Raw honey *.		Bacillus coagulans GBI-30 6086.
	BVRG14	Apple juice, lemon juice.	Red cabbage juice, ginger juice.		Inulin.	Bacillus cultures
Peru	BVRG15	Apple juice concentrate, golden berry juice, natural guarana extract, natural golden berry flavouring.	Natural turmeric extract, natural guayusa extract.	Natural maca extract
	BVRG16	Cranberry juice concentrate, apple juice concentrate, acai juice, natural acai flavor.	Natural purple corn extract.
	BVRG17	Apple juice concentrate, camu camu juice, natural camu camu flavouring.	Natural ginger extract.	Natural eucalyptus extract.
	BVRG18	Carrot juice, apple juice concentrate, passion fruit juice, aguaje juice, natural passion fruit flavour.			Vitamin A.

* Organic products.

, Figure 1). The samples were kept at a temperature of 4 °C until the analysis.

For the bioactive compound analysis, extracts were obtained from the beverages as follows: 1.5 g of sample was placed in a Falcon tube (15 mL) with 5 mL of methanol 80%. The mixture was vortexed (Thermo Scientific, Daejeon, Republic of Korea) for 15 min at 1000 rpm. The samples were sonicated for 30 min in an ultrasonic bath (CPX5800H-E, Branson, Danbury, CT, USA) at a frequency of 40 kHz and 25 °C. Then, the samples were centrifuged (5810R, Eppendorf, Hamburg, Germany) at 3500 rpm for 30 min. The recovered supernatant was stored at −20 °C until further testing.

2.2. Physicochemical Analysis

The acidity was measured according to the AOAC Method 942.15. [16] and the results were expressed as g/100 mL of beverages. The total soluble solids were determined using the AOAC Method 932.12. [17], and the results were expressed as °Brix. The H ion activity was measured following the AOAC Method 981.12. (pH of acidified foods) [18] and the results were expressed as pH values.

2.3. Nutritional Quality (Solo Citar, Método, Fundamento, y Colocar Las Modificaciones)

The proximate analysis included the following variables. The moisture content was determined according to the AOAC method 920.151 [19]. Using a forced air heater (UF160, Memmert, Schwabach, Germany), the moisture content was determined. A sample weighing about 2 g was put on a Petri plate and dried at 100 °C until it reached a constant weight.

For the estimation of ashes, the AOAC method 940.26 [20] was applied. Each sample weighed 2 g, and was then added to porcelain crucibles that had already been weighed. After that, the sample was brought to a muffle furnace (1500 FD1535M, Thermo Scientific, Waltham, MA, USA) and burned for five hours at 550 °C.

The protein amount was measured using the Kjeldahl system. A 5 g sample was taken and placed in the digestion tubes. A catalyst and sulphuric acid were added, and the mix was digested in the Kjeldatherm-KT8S (Gerhardt, Königswinter, Germany) until emeraldine was obtained. The digestion tubes were then cooled at room temperature and the samples distillated in the Vapodest 450 (Gerhardt, Königswinter, Germany); finally, the titration process was performed on the Titroline 5000 (SI Analytics, Sandton, South Africa). The results were expressed as total protein in g/100 g sample.

The fat content was quantified following the AOAC method 983.23 [21]. In brief, 5 mL of the sample was transferred to a 50 mL tube, and 1% of Clarase 40,000^® in 0.5 M sodium acetate was added until the total volume reached 32 mL. The mixture was thoroughly agitated and incubated in a water bath at 45–50 °C for one hour, and after this time, the sample was thoroughly mixed and then transferred to a homogenizer (Omni Mixer-Homogenizer, Omni International, Waterbury, CT, USA). The sample tube was initially rinsed with 80 mL of methanol, followed by 40 mL of chloroform, and the rinses were subsequently incorporated into the homogenizer. The mixture was agitated at high velocity for 2 min, after which 40 mL of chloroform was included, and the mixture was agitated for an additional 30 s. After that, 30 more seconds were spent mixing the contents after adding 40 mL of water. To make the chloroform layer (bottom layer) more visible, the extract was put into a 500 mL siliconized polypropylene bottle, sealed, and centrifuged for 10 min at 3000 rpm. Before dispensing, the bottle was submerged in a water bath set at 25 °C for 15 min for acclimatization. Then, the proportion (%) of fats was calculated.

The crude fiber was determined by the filter bag technique of AOCS [22] from the sample that was defatted before and hydrolyzed in an alkaline (1.25% sodium hydroxide) and double acid (1.25% sulfuric acid) conditions. The crude fiber was calculated by comparing the dry weight of the stove with the amount of organic matter destroyed in the muffle furnace.

The carbohydrate content and total energy were calculated according to the method described by Reyes García et al. [23], which determines the difference between the sum of the values obtained for humidity, protein, fat, and ash. The results were expressed in relative values (%), except for energy (Kcal/100 mL).

2.4. Total Phenolic Compounds

The total polyphenol content was determined according to the Folin–Ciocalteu method adapted by Alim et al. [24]. Standard Gallic acid solution (10 mg/mL) was prepared with 80% methanol to obtain a calibration curve (y = 0.0064x + 0.0405). At least 100 μL of sample was mixed with 750 μL of Folin–Ciocalteu (0.2N) reagent, and 750 μL of 7.5% was added. After 2 h of reaction at room temperature in the dark, the absorbance was measured at 765 nm in a spectrophotometer (V-770, Jasco, Japan). Finally, the concentration was calculated, extrapolating the values on the calibration line, and the results were expressed as gallic acid equivalents per 100 mL of beverage (mg GAE/100 mL).

2.5. Total Anthocyanins

The total anthocyanins was quantified following the pH differential method by AOAC 2005.02 [25]. An aliquot of 2.5 mL of sample was placed into a Falcon tube of 15 mL. Then, 2.5 mL of ethanol (96%):HCL (1.5 M) (85:15 v/v) was added. The mixture was shaken for 15 min in a vortex (Thermo Scientific) at 1000 rpm. Then, the mix was sonicated for 15 min in an ultrasonic bath (CPX5800H-E, Branson, Branson, Danbury, CT, USA) at 40 kHz and 25 °C, followed by centrifugation at 3500 rpm for 30 min. The supernadant:buffer (1:4, v/v) at pH 1 (KCl a 0.025 M) and supernadant:buffer (1:4, v/v) at pH 4.5 (CH₃COONa.3H₂O a 0.4 M) were measured at 520 and 700 nm. The results for the total anthocyanins content were expressed as mg cyanidin-3-glucoside per 100 mL of beverage (mg Cyanidin 3-glucoside/100 mL).

2.6. Total Carotenoids

The carotenoid extraction of the beverages was performed following the method described by Zanqui et al. [26] A 10 mL sample was extracted with 10 mL of n-hexane. The recovered extract was kept in dark tubes and the absorbance was measured at 450 nm using a spectrophotometer (V-770, Jasco, Japan). The β-carotene (μg/mL) content was calculated using the following Equation (1):

$$\mathsf{\beta }-\mathrm{carotene} (\mathsf{\mu }\mathrm{g}/\mathrm{mL})={\displaystyle \frac{(ABS.V.{10}^4)}{W.E_{1cm}^{1\%}}}$$

(1)

where ABS is the absorbance value, V is the volume of the solvent, W is the volume of the sample and $E_{1cm}^{1\%}$ is the extinction coefficient of β-carotene (E1% = 2592), and the results were expressed as mg β-carotene per 100 mL of beverage (mg β-carotene/100 mL).

2.7. Vitamin C Content

The vitamin C was determined by the 2,6-dichloroindophenol Titrimetric Method of AOAC 967.21 [27]. Vitamin C standard and indophenol solution were used freshly. Then, 1 mL of sample or standard was mixed with 1 mL of HPO₃–CH₃COOH solution. Next, this was titrated with indophenol solution until a pinkish-pink color change was evident. The results were expressed as mg/100 mL.

2.8. DPPH Assay

The 2,2-Diphenyl-1-picrylhydrazyl (DPPH^∙) free radical scavenging activity of the extracts was determined using the method proposed by Alim et al. [24]. This method is based on the donation of an electron to the DPPH^∙ radical, causing its reduction, and this is manifested by a color change from violet to yellow. Thus, 100 μL of the sample was mixed with 900 μL of DPPH^∙ radical solution (100 μmol/L) and then allowed to stand for 30 min at room temperature. The absorption was measured at 515 nm using a spectrophotometer (V-770, Jasco, Japan). The percent inhibition (% I) of the samples was calculated by employing Equation (2):

$$\%\mathrm{I}=\left({\displaystyle \frac{\left(A0-A1\right)}{A0}}\right)\times 100$$

(2)

where A0 is the initial absorbance of the control (DDPH^∙ radical) and A1 is the final absorbance in the presence of the sample. A calibration curve of Trolox standard (y = 2170.5x + 9.0672) was used in the same conditions and the results were expressed as µmol of Trolox equivalent per mL of beverage (µmol TE/mL).

2.9. FRAP Assay

The Ferric Reducing Antioxidant Power assay was performed following the method described by Martínez and Ramos-Escudero [28]. The FRAP reagent was prepared by mixing acidified HCL solution at pH 3.6 with 10 mmol/L of 2,4,6-Tripyndyl-s-triazine and 20 mmol/L of a solution of ferric chloride. The reaction was started by mixing 120 μL of sample with 750 μL of FRAP solution. The mixture was left to stand for 10 min at room temperature, and the absorbance was determined at 593 nm. The results were expressed as μmol of ferrous sulphate per mL of beverage (µmol FeSO₄/mL).

2.10. Polyphenol Profile by HPLC-DAD

Before the analysis, the method described by Barriga-Sánchez et al. [29] was used. The method was carried out with a High-Performance Liquid Chromatograph Chromaster with a diode array detector (Hitachi High-Technologies Corporation, Tokyo, Japan). The compounds were separated using a LiChrospher^® 100 RP-18 end-capped, 5 µm, 4 × 250 mm cartridge (Millipore, Darmstadt, Germany) column at 30 °C. An injection volume of 20 μL and a flow rate of 1 mL min⁻¹ were used with a solvent elution of 0.5% of orthophosphoric acid in water as mobile phase A and another mixture of MeOH:acetonitrile (50:50 v/v) was used as mobile phase B. The following gradient system was used: 0–25 min, linear from 95–70% A; 25–35 min, linear from 70 to 62% A; 35–40 min, isocratic 62% A, 40–45 min, linear from 62 to 55% A%; 45–50 min, linear from 55 to 47.5% A; 50–55 min, linear from 47.5 to 95% A; and 55–60 min, isocratic 95% A. The retention periods and UV spectra of the extracts with the standards were used to identify and quantify the phenolic components.

2.11. Statistical Analysis

All the experiments were performed in triplicate and expressed as mean ± standard deviation (SD). Analysis of variance (ANOVA) was used to test the significance of each variable (p < 0.05) and Tukey’s test method was performed for the multiple mean comparison; a significance level of 5% (p < 0.05) was considered statistically significant. The analyses were conducted using R-Studio software version 4.3.2 (Boston, MA, USA) [30]. The relationship between the variables TPC, vitamin C, DPPH, and FRAP in the beverages was determined by calculating the Pearson correlation coefficient using a SRplot online platform [31].

3. Results and Discussion

3.1. Physicochemical Characteristics

The acidity values of the functional beverages are shown in

Table 2. Physicochemical analysis of functional beverages.

Beverages	Acidity (g/100 mL)	Total Soluble Solids (°Brix)	pH
BVRG1	3.0 ± 0.0 a	12.0 ± 0.0 i	2.9 ± 0.0 l
BVRG2	2.2 ± 1.7 a	13.0 ± 0.0 g	3.7 ± 0.0 c
BVRG3	3.0 ± 2.4 a	16.0 ± 0.0 a	3.4 ± 0.0 e
BVRG4	3.0 ± 2.4 a	7.5 ± 0.0 n	3.3 ± 0.0 e
BVRG5	4.2 ± 3.3 a	13.5 ± 0.0 d	3.1 ± 0.0 i
BVRG6	2.4 ± 1.9 a	7.0 ± 0.0 o	3.1 ± 0.0 h
BVRG7	3.2 ± 2.5 a	7.5 ± 0.0 n	2.2 ± 0.0 o
BVRG8	3.5 ± 2.8 a	8.5 ± 0.0 l	2.9 ± 0.0 n
BVRG9	3.4 ± 2.7 a	6.5 ± 0.0 q	2.9 ± 0.0 m
BVRG10	2.9 ± 2.2 a	13.4 ± 0.0 e	3.1 ± 0.0 hi
BVRG11	3.5 ± 2.7 a	6.9 ± 0.0 p	3.3 ± 0.0 f
BVRG12	0.9 ± 0.7 a	9.7 ± 0.0 k	4.3 ± 0.0 a
BVRG13	1.1 ± 0.9 a	14.0 ± 0.0 c	4.1 ± 0.0 b
BVRG14	2.1 ± 1.6 a	10.2 ± 0.0 j	3.4 ± 0.0 e
BVRG15	1.4 ± 1.1 a	14.5 ± 0.0 b	3.6 ± 0.0 d
BVRG16	1.4 ± 1.1 a	12.8 ± 0.0 h	3.0 ± 0.0 k
BVRG17	1.8 ± 1.4 a	8.0 ± 0.0 m	3.2 ± 0.0 g
BVRG18	1.5 ± 1.2 a	13.2 ± 0.0 f	3.1 ± 0.0 j
p-value	0.937	0.000	0.000

Means in the same row with different superscript letters (a–p) were significantly different according to Tukey’s honest significant difference test (p < 0.05).

. Acidity is a quality parameter that serves to ensure that products comply with regulatory requirements and do not pose a risk to the safety or health of consumers. The acidity values ranged between 0.92 and 4.23, and no significant differences were determined. The beverage with the lowest acidity value was the one made mainly from turmeric and carrot juice (BVRG12).

Total soluble solids (°Brix) is a parameter used to determine the total amount of sucrose dissolved in a beverage. A wide range of values (6.5–14.5) were obtained from the functional beverages evaluated (Table 2), exhibiting significant differences (p < 0.05). Values < 10 °Brix include drinks with apple cider vinegar, acerola, turmeric tonic, and ginger as ingredients. Meanwhile, the highest amount of sugar was obtained in the beverage made with apple juice concentrate (BVRG15).

The potential hydrogen (pH) is a parameter that measures the degree of acidity or alkalinity of a substance, expressed in values ranging from 0 (most acidic) to 14 (most alkaline), with the midpoint (7) being the neutral value. The pH values of functional beverages are shown in Table 2. All samples are in the range of 2–4, and significant differences were determined between the results. Also, the beverage based on turmeric tonic (BVRG12) reached a pH of 4.26.

3.2. Nutritional Quality

The results of the proximate analysis are shown in

Table 3. Proximate analysis of functional beverages.

Beverages	Moisture *	Ashes *	Proteins *	Fats *	Crude Fiber *	Carbohydrates *	Total Energy **
BVRG1	87.56 ± 0.02 h	0.62 ± 0.01 b	0.75 ± 0.00 b	ND	0.08 ± 0.01 c	11.08 ± 0.04 g	47.29 ± 0.15 i
BVRG2	87.25 ± 0.03 i	0.56 ± 0.00 c	0.6 ± 0.02 de	ND	ND	11.59 ± 0.05 f	48.73 ± 0.1 h
BVRG3	83.97 ± 0.02 n	0.71 ± 0.00 a	0.69 ± 0.01 c	ND	ND	14.63 ± 0.03 a	61.28 ± 0.09 a
BVRG4	92.67 ± 0.02 a	0.19 ± 0.00 jk	0.12 ± 0.01 ij	ND	0.05 ± 0.04 c	7.01 ± 0.03 n	28.52 ± 0.06 p
BVRG5	86.37 ± 0.01 k	0.33 ± 0.01 g	0.55 ± 0.00 e	0.62 ± 0.01 a	ND	12.13 ± 0.03 e	56.34 ± 0.04 c
BVRG6	92.54 ± 0.00 b	0.31 ± 0.01 g	0.56 ± 0.01 e	0.21 ± 0.01 d	ND	6.39 ± 0.02 o	29.66 ± 0.02 o
BVRG7	91.51 ± 0.02 e	0.55 ± 0.01 c	0.56 ± 0.03 e	0.01 ± 0.01 f	0.04 ± 0.00 c	7.37 ± 0.02 l	31.8 ± 0.09 n
BVRG8	91.6 ± 0.00 e	0.23 ± 0.02 ijk	0.22 ± 0.00 h	ND	ND	7.96 ± 0.02 k	32.69 ± 0.09 m
BVRG9	92.42 ± 0.01 c	0.39 ± 0.01 f	0.17 ± 0.02 hi	ND	ND	7.03 ± 0.01 n	28.78 ± 0.1 p
BVRG10	87.28 ± 0.06 i	0.29 ± 0.00 gh	0.89 ± 0.00 a	ND	ND	11.53 ± 0.06 f	49.69 ± 0.22 g
BVRG11	90.35 ± 0.04 f	0.49 ± 0.01 d	0.44 ± 0.00 f	ND	ND	8.72 ± 0.03 j	36.64 ± 0.12 l
BVRG12	90.14 ± 0.01 g	0.43 ± 0.02 ef	0.58 ± 0.01 e	ND	ND	8.86 ± 0.02 i	37.73 ± 0.12 k
BVRG13	85.84 ± 0.01 m	0.47 ± 0.01 de	0.64 ± 0.02 cd	ND	0.02 ± 0.01 c	13.05 ± 0.00 c	54.78 ± 0.09 e
BVRG14	90.19 ± 0.01 g	0.25 ± 0.00 hi	0.38 ± 0.01 fg	ND	ND	9.18 ± 0.00 h	38.25 ± 0.04 j
BVRG15	85.92 ± 0.00 m	0.23 ± 0.01 ijk	0.34 ± 0.01 g	0.04 ± 0.01 e	ND	13.46 ± 0.02 b	55.6 ± 0.03 d
BVRG16	86.07 ± 0.01 l	0.19 ± 0.00 k	0.4 ± 0.00 f	0.48 ± 0.01 b	0.48 ± 0.00 a	12.86 ± 0.00 d	57.35 ± 0.12 b
BVRG17	92.06 ± 0.02 d	0.24 ± 0.01 ij	0.2 ± 0.01 h	0.27 ± 0.00 c	0.25 ± 0.01 b	7.23 ± 0.03 m	32.16 ± 0.09 n
BVRG18	87.01 ± 0.00 j	0.08 ± 0.02 l	0.09 ± 0.00 j	ND	0.01 ± 0.00 c	12.82 ± 0.02 d	51.66 ± 0.07 f
p-value	0.000	0.000	0.000	0.000	0.000	0.000	0.000

* Data were expressed in relative values (%). ** Data were expressed in Kcal/100 mL of beverage. Means in the same row with different superscript letters (a–p) were significantly different according to Tukey’s honest significant difference test (p < 0.05). ND: not detected.

. It can be observed that there are significative differences (p < 0.05) between the beverages studied. The mean of the moisture values in the samples was 89 ± 2.8%, while most of the samples had an ash content between 0.2 and 0.7%.

Regarding macromolecules (Table 3), all beverages had a protein content of less than 1%, and the fat content was only determined in five samples, in a range between 0.01 and 0.62%. Also, the crude fiber proportion was less than 0.5% in the samples that were determined. Regarding the carbohydrates in beverages, it was determined that the content ranged from 6 to 15%. Based on these results, total caloric values of up to 61.3 Kcal/100 mL of beverage were calculated. It should be noted that the drinks contained no added sugars, so the carbohydrates determined came naturally from their ingredients. In this sense, these types of beverages would not affect the glycemic index of those who consume it, as was examined with native Peruvian fruits by obtaining a low glycemic level (≤55) after the consumption of guanabana, sachatomate, goldenberry and tumbo serrano [32]. Some of these fruits were used as ingredients in Peruvian plant-based beverages; therefore, it would be interesting to determine the glycemic index of these beverages in a subsequent study.

These drinks are not produced with nutritional concerns, such as protein or energy, as the observed values indicate their very low-calorie intake, making it clear that the benefit of these beverages is based on other substances they contain, and different types of benefits.

3.3. Bioactive Compounds and Antioxidant Activity

Bioactive compounds are secondary metabolites of plants that have antioxidant and protective properties.

Table 4. Bioactive compounds and antioxidant activity of functional beverages.

Beverages	Total Polyphenols (mg GAE/100 mL)	Total Anthocyanins (mg Cyanidin 3-Glucoside/100 mL)	Total Carotenoids (mg ß-Carotene/100 mL)	Vitamin C (mg/100 mL)	DPPH (µmol TE/mL)	FRAP (µmol FeSO4/mL)
BVRG1	31.13 ± 0.09 k	ND	6.57 ± 0.35 c	34 ± 0.00 g	0.09 ± 0.00 kl	0.13 ± 0.00 gh
BVRG2	135.9 ± 0.84 d	5.45 ± 0.02 a	ND	ND	0.48 ± 0.01 c	0.71 ± 0.09 c
BVRG3	76.84 ± 0.43 e	ND	1.41 ± 0.13 d	78.2 ± 0.05 d	0.15 ± 0.00 ij	0.14 ± 0.01 gh
BVRG4	26.98 ± 0.36 l	ND	ND	ND	0.10 ± 0.00 k	0.11 ± 0.00 gh
BVRG5	57.48 ± 0.28 f	ND	7.18 ± 0.37 c	61.9 ± 0.48 e	0.17 ± 0.00 hi	0.19 ± 0.01 fgh
BVRG6	398.3 ± 0.77 a	ND	1.23 ± 0.01 d	240.2 ± 1.0 b	2.09 ± 0.01 b	3.03 ± 0.11 a
BVRG7	51.52 ± 0.66 gh	ND	0.62 ± 0.01 d	ND	0.24 ± 0.00 f	0.11 ± 0.00 h
BVRG8	57.79 ± 0.22 f	0.62 ± 0.01 c	ND	81.9 ± 0.48 c	0.33 ± 0.00 e	0.42 ± 0.01 d
BVRG9	42.25 ± 0.22 i	ND	0.54 ± 0.17 d	7.17 ± 0.48 h	0.21 ± 0.00 g	0.19 ± 0.02 efgh
BVRG10	36.93 ± 0.56 j	0.11 ± 0.01 d	ND	0.67 ± 0.00 j	0.14 ± 0.00 j	0.19 ± 0.01 fgh
BVRG11	52.40 ± 0.00 g	ND	0.19 ± 0.00 d	0.67 ± 0.00 j	0.19 ± 0.00 h	0.34 ± 0.00 def
BVRG12	29.22 ± 0.54 kl	ND	19.15 ± 2.94 a	0.67 ± 0.00 j	0.07 ± 0.00 l	0.09 ± 0.00 h
BVRG13	58.94 ± 0.28 f	ND	6.63 ± 1.04 c	0.67 ± 0.00 j	0.15 ± 0.00 ij	0.35 ± 0.00 de
BVRG14	48.88 ± 1.13 h	ND	ND	4.44 ± 0.57 i	0.15 ± 0.00 ij	0.26 ± 0.00 efg
BVRG15	42.60 ± 0.28 i	ND	7.32 ± 0.44 c	34.6 ± 0.06 g	0.17 ± 0.00 hi	0.16 ± 0.01 gh
BVRG16	140.3 ± 1.08 c	3.08 ± 0.13 b	ND	2.49 ± 0.29 ij	0.43 ± 0.00 d	0.70 ± 0.01 c
BVRG17	53.82 ± 0.71 g	ND	13.82 ± 0.65 b	46.7 ± 0.48 f	0.24 ± 0.00 f	0.16 ± 0.01 gh
BVRG18	345.9 ± 2.13 b	0.70 ± 0.06 c	ND	460 ± 1.43 a	2.24 ± 0.02 a	1.31 ± 0.04 b
p-value	0.000	0.000	0.000	0.000	0.000	0.000

Means in the same row with different superscript letters (a–l) were significantly different according to Tukey’s honest significant difference test (p < 0.05). ND: not detected.

shows significant differences (p < 0.05) in the content of total polyphenols, anthocyanins, carotenoids, and vitamin C, as well as in the antioxidant activity values assessed by DPPH and FRAP methods. The difference in the content of these substances lies in the ingredients used in the production of the beverages.

The results in Table 4 show that the total polyphenols ranged between 27 and 398 mg GAE/100 mL. A range of 51.70–62.59 mg GAE/100 mL was determined in a beverage made with mango, passion fruit and cashew apple [33]. Anthocyanins were only quantified in five beverages. The highest content of total carotenoids was determined in a beverage made with turmeric concentrate (BVRG12). The beverages with a major content of vitamin C were a sample made with acerola, pineapple, ginger, and lemon juice (BVRG6), and a beverage made with a concentrate of carrot, apple, passion fruit and aguaje juice (BVRG18), respectively. A previous study also found that the vitamin C content was higher in acerola than in fruits such as acai and apple [34]. On the other hand, it should be mentioned that even if certain samples have a significant carotenoid content, these compounds’ effectiveness as an antioxidant may be enhanced by their synergistic interaction with other compounds like vitamin C, as it increases their stability and prevents oxidation [35,36].

Regarding antioxidant activity, the main components that fend off a variety of diseases brought on by oxidative stress caused by reactive oxygen and reactive nitrogen species are bioactive compounds, including polyphenols and vitamin C [37]. Also, beverages with ingredients such as acerola and camu camu have been reported to be high in polyphenols and antioxidants [34]. In the present study, the beverages with the highest antioxidant activity were the samples BVRG6 and BVRG18, according to both methods applied. However, the results showed lower levels of antioxidant activity in the beverage made camu camu (BVRG17). It is worth mentioning that samples BVRG6 and BVRG18 were the ones with the highest TPC content. In light of these findings, a correlation study was performed with the values of total polyphenols, vitamin C, and antioxidant activity. As can be observed in Figure 2, there is a positive and strong correlation between total polyphenols, vitamin C and the DPPH and FRAP values, showing that these bioactive compounds are the main contributors to the antioxidant activity of the samples. In relation to this, different studies have also shown that the antioxidant activity of polyphenols is increased in the presence of vitamin C, as they have a synergistically stabilizing effect [38,39].

Although no recommended doses for the intake of phenolic compounds, or specifically anthocyanins, have been established, their importance and health benefits are recognized [40]. And the consumption of some of the beverages analyzed contributes to the intake observed in Europe [41] and the United States [6] in the young population, if they are consumed according to the proposed dose of the beverages. Regarding carotenoid intake, the focus is on provitamin A compounds, given the associated interests and benefits. The beverages that were rich in carotenes (BVRG12 and BVRG17) would provide the Recommended Dietary Allowance (RDA) for vitamin A (10.8 mg/day of ß-carotene) [42]. Regarding vitamin C, the RDA is 95–110 mg/day (healthy adults) [43], and as observed in this study, these values are achieved via the intake of the analyzed beverages in their commercial serving size. However, it is important to note that two of the samples exceed the stated requirement of vitamin C and should not be over-consumed to avoid some adverse reactions such as diarrhea, nausea, abdominal cramps and other gastrointestinal disorders due to the osmotic effect of the unabsorbed vitamin C content in the gastrointestinal tract [44,45].

In addition to the content of bioactive compounds in foods, their bioavailability is of paramount importance in establishing recommendations, because many dietary and host-related factors can affect the actual intake and benefits of these substances. Therefore, it is recommended that the intake of five servings of fruit and vegetables per day is maintained, as these foods provide a natural and healthy supply of these substances; however, in cases where they are necessary, one can resort to products with a higher concentration of these compounds and that come from natural sources. As can be seen, regardless of the origin of the beverages (in this study from the United States and Peru), the ingredients used increase the concentration of the bioactive compounds of interest.

3.4. Polyphenols Profiles

Table 5. Polyphenol profile of functional beverages.

Beverages	Caffeic Acid	Chlorogenic Acid	3,4-Dihydroxy-Benzoic Acid	Ferulic Acid	Gallic Acid	2-Hydroxy-Cinnamic Acid	4-Hydroxy-Phenylacetic Acid	Luteolin	Quercetin	Rutin	Sinapic Acid	Syringic Acid	Vanillin	Vanillic Acid
BVRG1	0.04 ± 0.00 h	ND	0.54 ± 0.00 b	0.27 ± 0.00 c	0.25 ± 0.00 hij	ND	0.09 ± 0.00 e	ND	ND	ND	0.37 ± 0.00 g	0.05 ± 0.00 e	0.02 ± 0.02 b	0.04 ± 0.00 a
BVRG2	0.21 ± 0.00 f	3.12 ± 0.03 c	0.63 ± 0.01 a	ND	3.04 ± 0.04 d	ND	0.81 ± 0.03 a	ND	0.62 ± 0.01 b	6.14 ± 0.08 a	ND	ND	0.02 ± 0.00 d	0.27 ± 0.00 a
BVRG3	ND	ND	0.02 ± 0.00 h	0.04 ± 0.00 k	0.09 ± 0.00 kl	0.02 ± 0.02 ab	0.09 ± 0.01 e	ND	ND	0.41 ± 0.01 d	0.45 ± 0.00 f	0.21 ± 0.00 b	0.03 ± 0.00 cd	0.30 ± 0.00 a
BVRG4	ND	2.16 ± 0.03 e	0.02 ± 0.00 gh	ND	0.02 ± 0.00 l	ND	0.58 ± 0.00 b	ND	ND	0.03 ± 0.00 fg	ND	ND	0.01 ± 0.00 d	ND
BVRG5	ND	0.08 ± 0.03 i	0.11 ± 0.00 d	0.08 ± 0.00 j	0.16 ± 0.00 jk	ND	0.10 ± 0.01 e	ND	0.05 ± 0.00 fg	0.71 ± 0.00 c	0.67 ± 0.03 d	0.10 ± 0.00 d	0.16 ± 0.00 cd	0.23 ± 0.00 a
BVRG6	0.04 ± 0.00 h	0.16 ± 0.11 hi	0.09 ± 0.00 e	0.13 ± 0.00 i	6.02 ± 0.11 b	ND	ND	ND	ND	ND	0.16 ± 0.00 i	ND	0.12 ± 0.00 cd	0.07 ± 0.00 a
BVRG7	0.02 ± 0.00 ij	0.29 ± 0.00 gh	ND	0.23 ± 0.00 ef	0.29 ± 0.00 hi	ND	0.34 ± 0.01 cd	ND	0.09 ± 0.00 de	0.24 ± 0.00 e	ND	ND	0.02 ± 0.00 d	0.02 ± 0.00 a
BVRG8	ND	2.59 ± 0.01 d	ND	0.21 ± 0.00 f	0.31 ± 0.00 h	ND	ND	ND	0.04 ± 0.00 g	ND	ND	ND	0.16 ± 0.00 cd	ND
BVRG9	ND	2.06 ± 0.08 e	0.02 ± 0.01 gh	0.31 ± 0.01 b	0.03 ± 0.00 l	ND	ND	ND	0.10 ± 0.00 d	ND	ND	ND	0.13 ± 0.00 cd	0.33 ± 0.46 a
BVRG10	0.26 ± 0.00 e	3.00 ± 0.00 c	0.05 ± 0.00 f	0.23 ± 0.00 de	1.30 ± 0.00 f	ND	ND	ND	0.07 ± 0.01 ef	ND	0.72 ± 0.01 c	ND	89.89 ± 0.07 a	0.09 ± 0.00 a
BVRG11	0.56 ± 0.00 c	2.67 ± 0.01 d	0.04 ± 0.00 fg	0.35 ± 0.00 a	2.31 ± 0.01 e	ND	ND	ND	0.03 ± 0.00 g	ND	0.99 ± 0.01 b	ND	0.18 ± 0.00 cd	0.03 ± 0.00 a
BVRG12	0.03 ± 0.00 hi	0.06 ± 0.00 i	ND	0.05 ± 0.00 k	0.22 ± 0.00 hij	ND	0.24 ± 0.01 de	ND	ND	ND	ND	0.02 ± 0.00 f	0.01 ± 0.00 d	0.11 ± 0.00 a
BVRG13	0.64 ± 0.00 b	ND	ND	0.25 ± 0.00 cd	0.09 ± 0.00 kl	0.03 ± 0.00 a	0.45 ± 0.00 bc	1.04 ± 0.02	ND	0.70 ± 0.00 c	0.61 ± 0.01 e	0.17 ± 0.00 c	ND	0.23 ± 0.00 a
BVRG14	0.79 ± 0.00 a	5.12 ± 0.01 b	ND	0.23 ± 0.00 de	0.09 ± 0.00 kl	ND	ND	ND	ND	0.40 ± 0.00 d	1.99 ± 0.00 a	ND	0.08 ± 0.00 cd	ND
BVRG15	ND	0.43 ± 0.00 g	0.02 ± 0.00 h	0.08 ± 0.00 j	0.81 ± 0.00 g	ND	0.82 ± 0.01 a	ND	ND	0.11 ± 0.00 f	0.08 ± 0.01 j	ND	16.85 ± 0.00 b	0.03 ± 0.00 a
BVRG16	0.29 ± 0.00 d	21.3 ± 0.02 a	0.62 ± 0.01 a	0.18 ± 0.00 g	0.18 ± 0.00 ijk	0.01 ± 0.00 b	0.18 ± 0.00 de	ND	0.82 ± 0.01 a	2.43 ± 0.01 b	0.26 ± 0.01 h	0.52 ± 0.00 a	0.23 ± 0.01 c	ND
BVRG17	0.15 ± 0.00 g	1.37 ± 0.00 f	0.14 ± 0.00 c	ND	3.17 ± 0.03 c	ND	0.24 ± 0.03 de	ND	ND	ND	ND	ND	ND	ND
BVRG18	0.01 ± 0.00 j	0.07 ± 0.00 i	ND	0.17 ± 0.00 h	9.10 ± 0.03 a	ND	0.56 ± 0.01 b	ND	0.30 ± 0.00 c	0.11 ± 0.00 f	ND	ND	ND	0.34 ± 0.02 a
p-value	0.000	0.000	0.000	0.000	0.000	0.010	0.000	NA	0.000	0.000	0.000	0.000	0.000	0.145

Means in the same row with different superscript letters (a–k) were significantly different according to Tukey’s honest significant difference test (p < 0.05). ND: not detected; NA: not applicable.

exhibits some individual polyphenol concentrations following each beverage analyzed. A total of 14 phenolic compounds were determined among all samples; however, gallic acid was the most common. This confirmed the statement that gallic acid is a common phenolic in plant materials [46]. The samples with the higher content of gallic acid were BVRG6 and BVRG18, originally made in the United States and Peru, respectively.

The compounds present in most of the samples were Chlorogenic acid, Ferulic acid and Vanillin, the latter compound being present in a high concentration in some samples. Another remarkable aspect is that Luteolin was only quantified in one of the samples (BVRG13), which was made from ginger and orange juice. These results are consistent with the statement that the ingredients used directly affect the resulting phenolic compound content in functional beverages. However, as it is not possible to have a ‘natural’ beverage formula that contains most compounds, as this would directly affect the sensory characteristics of the final product, formulas with different ingredient combinations that will be consumed according to the demand for the functionalities of interest must be proposed.

It should also be borne in mind that such products should not be confused with food supplements, let alone replace the natural consumption of fruits or vegetables. However, in vitro and in vivo studies are needed to determine the effects of the consumption of these functional drinks on health and to determine adequate doses for the optimal use of the bioactive compounds of interest. It is also important to note that, since phenolic compounds have different structures, their absorption is unchanging. Therefore, a study on the bioavailability of the phenols in these beverages would provide additional insights into the potential benefits of consuming these types of beverages. The sole recommendation that can be given is to eat a diet containing a range of fruits and vegetables, in addition to plant-based beverages, to supply an adequate number of bioactive components that both preserve and promote health.

4. Conclusions

The present study analyzed different functional beverages to determine their bioactive compounds and antioxidant activity, in addition to their nutritional composition. While different ingredients were used for each formulation, significant differences were observed in the results obtained. The nutritional values show that the consumption of these beverages offer a low-calorie contribution to the diet. For instance, the most important aspect of these types of products is the bioactive compound content, because there are functional effects associated with these biochemicals that could be potentially covered by future research. This study demonstrates that the plant beverages examined may offer a significant number of bioactive compounds associated with ingredients used, supporting customer preferences. This study also shows that the use of Peruvian plant resources in products such as functional beverages is beneficial due to the nutritional value and the various types of antioxidants found in other food formulations.