Sensorially accepted Mangifera indica and Myrciaria dubia yogurts with high ascorbic acid content

Barrios Renteria, Juan Carlos; Espinoza-Espinoza, Luis Alfredo; Valdiviezo-Marcelo, Jaime; Moreno-Quispe, Luz Arelis

doi:10.3389/fsufs.2022.999400

ORIGINAL RESEARCH article

Front. Sustain. Food Syst., 18 October 2022

Sec. Nutrition and Sustainable Diets

Volume 6 - 2022 | https://doi.org/10.3389/fsufs.2022.999400

Sensorially accepted Mangifera indica and Myrciaria dubia yogurts with high ascorbic acid content

$\nJuan Carlos Barrios Renteria&#x;$ Juan Carlos Barrios Renteria¹^†

Luis Alfredo Espinoza-Espinoza¹^*^†

Jaime Valdiviezo-Marcelo¹

Luz Arelis Moreno-Quispe²

¹Laboratory Functional Food and Bioprocessing, Department of Food Engineering, Universidad Nacional de Frontera, Sullana, Peru
²Faculty of Business Sciences and Tourism, Universidad Nacional de Frontera, Sullana, Peru

Ascorbic acid deficiency has been associated with several health conditions. The objective of this study was to evaluate the content of ascorbic acid and the sensorial qualities of Mangifera indica and Myrciaria dubia yogurts. Four yogurt treatments were elaborated with different concentrations of these fruits (T1: 15% and 5%; T2: 15% and 10%; T3: 20% and 5% and T4: 20% and 10%) respectively, compared with a control treatment (CT: yogurt with 15% of Fragaria vesca). The ascorbic acid contents of the different treatments were determined by spectrophotometry, with values in the following order (T1: 63.2 mg/100 g; T2:114.3 mg/100 g; T3: 57.3 mg/100 g; T4: 115.1 and the control treatment CT:11.5 mg/100 g). The sensorial evaluation consisted of the application of a hedonic scale of 5 points (1: I dislike it very much; 2: I dislike it; 3: I neither like it nor dislike it; 4: I like it; 5: I like it a lot), results show evidence that the acidity level had a significant influence during the sensory evaluation. Treatment (T3) showed the greatest preference. The use of Mangifera indica and Myrciaria dubia in the treatments studied ensured ascorbic acid concentrations compared to the control treatment. This was significantly appreciated by consumers when the percentage of Myrciaria dubia was less than 10% of the total mass of the yogurt.

Introduction

Vitamin C or ascorbic acid (AA) is a water-soluble organic compound with high antioxidant power (Toh and Wilson, 2020; Lie and Liu, 2021), which is obtained mainly from fresh fruits or vegetables. Humans cannot produce it themselves, unlike most animals (Griffiths, 2020; Kang et al., 2020). Ascorbic acid is necessary for the production of various important chemical substances for the body. Such as collagen, neurotransmitters, cortisol, l-carnitine, vasopressin and catecholamines among others; it is also necessary for homeostasis and cellular function (Hoang et al., 2020). The nutritional deficiency of ascorbic acid in food diets causes various health problems such as anemia, scurvy, bleeding gums, muscle atrophy, poor wound healing, increased sensitivity to stress and a weakened the immune system (Singh and Prasad, 2018). These conditions can limit the return to normal homeostasis in cases of sepsis, a potentially fatal condition for the individual who suffers from it, whose deregulation of the body's immune response to an infection alters the intestinal barrier and the dysbiosis of the present microbiota (Figure 1), giving as a result the translocation of molecular patterns associated with intestinal pathogens (Haak et al., 2018; Zhang et al., 2022). In this same sense, 40% of the Peruvian child population under 3 years of age suffers from anemia due to iron deficiency (CEPLAN, 2021). Iron deficiency anemia is often caused by poor absorption of non-heme iron due to the presence of inhibitory compounds in the diet (Suri et al., 2020). However, food rich in ascorbic acid can improve the fixation of this mineral in the body (Liberal et al., 2020; Bhatnagar and Padilla-Zakour, 2021).

FIGURE 1

Figure 1. Mechanism of sepsis and microbial behavior at the intestinal level. Based on Zhang et al. (2022). DAMPs, damage-associated molecular patterns; LSECs, hepatic sinusoidal endothelium; PAMPs, pathogen-associated molecular patterns. In sepsis several mechanisms disrupt the intestinal barrier, including apoptosis of intestinal epithelial cells; disrupting the mucosal layer and intercellular junctions, generating a translocation of intestinal pathogen-associated molecules into the liver via lymphatic vessels or the biliary tract in response to the spread of PAMPs and DAMPs and systematic inflammation.

The recommended doses of ascorbic acid are 90 and 75 mg/day in adult men and women, respectively (Castillo Velarde, 2019), in children, ascorbic acid deficiency is called Moeller-Barlow disease, which delays wound healing (Qureshi et al., 2020). The recommended dose in children 1–3 years is 15 mg/day (Bastías Montes and Cepero, 2016). Ascorbic acid deficiency in pregnant women, often leads to serious problems in the fetus's brain (Tveden-Nyborg et al., 2012), therefore, it is recommended to consume doses of at least 10–20 mg/day of ascorbic acid for pregnant women and 20–60 mg/day for lactating women to compensate their daily requirements (Rowe and Carr, 2020; Carr and Lykkesfeldt, 2021). Child intake is poor in ascorbic acid, and some fruits could offer it (Aghili et al., 2012). Among the main fruits with a high content of ascorbic acid is possible to cite camu camu (Myrciaria Dubia) with 5043.51 to 6110 mg/100 g (Santos et al., 2021, 2022), Citrus genus fruit from 24.22 to 74.85 mg/100 g (Coelho et al., 2021), strawberry (Fragaria ananassa) from 52.82 to 55.66 mg/100 g (Aubert et al., 2021) and mango (Mangifera indica) from 9.52 to 52.27 mg/100 g (Qureshi et al., 2020).

M. dubia (camu camu) is a typical Amazonian fruit, known for its high content of ascorbic acid, which is 100 times higher than most citrus fruits, and attracts national and international commercial interest, in food, pharmaceutical and nutraceutical industries, due to its potential benefits for health (Abreu et al., 2020; Santos et al., 2021). Perú is the main exporter of M. dubia, and markets it in the form of flour, capsules, extract and dehydrated (Azevedo et al., 2019). In 2020, the joint export of these products based on M. dubia was 327.48 tons, with an FOB value of US$ 4.48 million (PROMPERU, 2021). Similarly, M. indica (mango), another fruit that provides significant amounts of ascorbic acid, is also a source of beta-carotene (which the human body can use to synthesize vitamin A), potassium, magnesium and fiber (Table 1); it is also highly demanded in the European market (Fratianni et al., 2020; Mishra et al., 2020). Piura region (Peru) is a reference in this crop, during 2020 around 132,000 tons were produced, representing 10.1% of the national participation (Sisagri et al., 2020).

TABLE 1

Table 1. Nutritional composition per 100 grams of pulp of M. dubia and M. indica.

Yogurt is a fermented dairy food produced by coagulating milk by adding starter cultures such as Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. Bulgaricus (Ahmad et al., 2022, 2023). This product is of great sensory acceptability and is considered a functional food due to its contribution in vitamins, minerals, proteins and fats (Ahmad et al., 2021), however, it lacks ascorbic acid, carotenoids and fiber (Salehi, 2021). This product is widely consumed by people of different ages, especially by infants. Its preparation also includes the addition of fruits to achieve a final product of greater acceptability (Mawad et al., 2015; Chandan, 2017; Freitas-Sá et al., 2018). Due to the growing trend of consumption of functional foods, research in the dairy sector has directed its efforts towards improving these functional and sensory properties (é and Lemos, 2020).

Yogurts produced by cow's and goat's milk, supplemented with L-ascorbic acid and powdered fruits, presented a high content of ascorbic acid between 17.44 and 17.14 mg/100 g, respectively. However, the highest sensory acceptability was found in cow's milk yogurts without the addition of ascorbic acid or fruit powder (Sobczak et al., 2022). Yildiz and Ozcan (2019) studied the effect of supplementation of yogurts with vegetable purees; and observed a higher content of ascorbic acid in yogurt with pumpkin puree with a concentration of 21.30 mg/Kg, in addition to a high sensory acceptability, content of polyphenols and total carotenoids. In other hand, Virgen-Ceceña et al. (2019) investigated the sensory and nutritional quality of yogurt with soursop (Annona muricata L.) at 15%. They obtained 11.25 mg/100g of ascorbic acid. Regarding general sensorial acceptability on a hedonic scale from 1 to 10, yogurt had a score of 7.8. Similarly, the study carried out by Sigdel et al. (2018) showed the addition of mulberry (Morus alba) osmo-dehydrated yogurt, increased ascorbic acid content from 0.77 mg/100 g to 5.96 mg/100 g, compared to conventional yogurt; in addition, the antioxidant capacity was increased due to the presence of phenolics and anthocyanins.

Since yogurt is a versatile dairy product that offers the possibility of substituting different fruits according to nutritional or sensory preferences (Granato et al., 2018; Guiné and Lemos, 2020), it was proposed to evaluate the ascorbic acid content and sensory qualities of yogurt using M. indica and M. dubia. With the incorporation of M. dubia, the aim was to increase the ascorbic acid content, while with M. indica, a pleasant sweet flavor was sought, balancing the acid-sweetness ratio and maintaining the sensory quality of the yogurts produced.

Materials and methods

Sachets of lactic culture of the brand SACCO LYOFAST SAB 446 B (Lactobacillus acidophilus and Bifidobacterium bifidum) purchased in the local market were used; camu camu (M. dubia) red variety originated from the San Martín region (Peru); Edward variety mango pulp was collected from local producers in Tambogrande, Sullana. Fresh whole milk was purchased from a local agricultural technical college. The equipment used was digital handheld pH meter—Hanna Instruments, Model HI991001, serial number B40848; a handheld refractometer—Yhequiomen, Model RHB0-90, Range 0–90%, Accuracy +/-1% Brix, Resolution 1% Brix; a spectrophotometer–Genesys, Model S-150, serial number 6287015.

Analysis of the density and pH of the raw material

Milk density was determined using a lactodensimeter calibrated at 15°C as described by Brousett-Minaya et al. (2015).

Analysis of pH and soluble solids content in the fruits

The determination of pH and soluble solids content of M. indica and M. dubia were performed with a handheld digital potentiometer—Hanna Instruments, Model HI991001 and a refractometer at 20°C, taking a sample of fruit pulp previously extracted in a 50 mL beaker in each case, according to the methodology of Cosme Silva et al. (2017) with modifications.

Processing of yogurt samples using Mangifera indica and Myrciaria dubia

Yogurts were made using a completely randomized bi-factorial design at 2²+1 of 2 variables (M. indica and M. dubia) with two levels in each case (15% and 20% of M. indica, as well as 5% and 10% of M. dubia), the control sample was strawberry yogurt (15% fruit), as it is the most offered product in supermarkets (Table 2).

TABLE 2

Table 2. Bi-factorial experimental design with control.

Preparation of the starter culture

One liter of UHT (Ultra High Temperature) milk was purchased in Tetrapak format at Tottus supermarket in the province of Sullana (Peru). The milk was poured into a 1.5-liter jug and the lyophilized culture envelope was dissolved, whose capacity to ferment is 100 liters of milk. The culture was separated into 50 ml fractions to ferment 5 liters of milk in each case, making a total of 20 culture fractions stored at freezing temperature (−22°C) until the moment of being inoculated during the yogurt fermentation process.

Pre-treatment of the fruit

The mangoes (M. indica) were cleaned and chopped manually with a knife. The mango is were heated on a stove top (100°C for 10 min) in a stainless-steel pan container, then cooled and stored at 5°C until use. Similarly, camu camu (M. dubia) peel and seeds were removed using a strainer, then heated on a stove at 100°C for 10 min, cooled and stored at refrigerated temperature until use.

Preparation of Mangifera indica and Myrciaria dubia yogurt

Yogurt preparation was carried out according to the procedure described by Moreira et al. (2017) with some modifications. The whole milk was kept at 5°C until processing, starting with a filtering process in a stainless-steel container, followed by pasteurization at 85°C for 5 min, constantly stirring to avoid the formation of crusts on the base of the container. Later it was subjected to cooling until reaching 43°C. The starter culture was inoculated and placed in a fermenter at 43°C for 5 h. The pH control was performed using a digital potentiometer. After the fermentation stage, the yogurt was left to stand at 5°C for 12 h. Then, four yogurt treatments of M. indica and M. dubia and a control of F. vesca were made, taking into account the amount of sugar provided by the different concentrations of fruits, it was considered to standardize the percentage of sugars present in all the formulations so this parameter did not influence significantly the sensorial evaluation. Finally, the product was packed in PET containers with a screw cap and stored at refrigeration temperature until their sensorial evaluation, as well as the development of the different analyses.

Physicochemical analysis of Mangifera indica and Myrciaria dubia yogurts

The analysis of all the treatments were carried out according to the following methods:

Determination of moisture by weight difference according to FIL-IDF 151:2005 method.

A 10 g sample was weighed in a Petri dish, then placed in a water bath to evaporate as much water as possible, then placed in an oven for 4 h at 105°C. The remaining residue was weighed and the moisture percentage was calculated, according to the following formula:

\begin{array}{l} % H u m i d i t y = [(W i - W f) / W f] \times 100 \end{array}

Where:

Wi: initial weight of the sample

Wf: final weight of the sample

Determination of ash content following the method of A.O.A.C. 945.46:2002.

A 2 g sample was weighed into a previously conditioned porcelain crucible for analysis. The sample was calcined in a muffle at 550°C for 5 h until completely white ashes were obtained. The crucibles were placed in a desiccator for 15 min and weighed on an analytical scale. The calculation of the ash content in the sample was carried out according to the following formula:

\begin{array}{l} % A s h e s = (W . r e s i d u e / W . s a m p l e) \times 100 \end{array}

Determination of fat content following the method of FIL-IDF 116A:1996.

Using the Rose-Göttlieb method, 5 g of yogurt were weighed and extracted in ammoniacal solution with diethyl ether and petroleum ether in three proportions. Then, by distillation and evaporation, the solvents were removed, determining the extracted fat content.

Determination of protein by the method of NTP 202.119:2014.

The concentration of nitrogen then converted to protein through a factor (6.38) was determined using the Kjeldahl method consisting of three steps, (1) digestion or mineralization with sulfuric acid, (2) distillation, and (3) titration. The calculations were made according to the following formula:

\begin{array}{l} % P r o t e i n = (14 \times N \times V \times 100 \times f a c t o r) / (m \times 1000) \end{array}

Where:

V: volume in mL of the acid used

N: normality of the acid used 0.1 N

m: sample mass in grams

Determination of carbohydrates by the method of differences of Collazos et al. (1993).

The carbohydrate content was obtained by difference subtracting 100% from the sum of all the percentages of moisture (H), ash (C), fat (G) and protein (P) using the following formula:

\begin{array}{l} % C a r b o h i d r a t o s = 100 - (H + C + G + P) \end{array}

Determination of total energy by method of Collazos et al. (1993).

To calculate the Kilocalorie content, the protein and carbohydrate content (in grams) were multiplied by 4 Kcal/g; the amount of fat (in grams) was multiplied by 9 Kcal/g and finally the results were added to obtain the total energy expressed in Kcal/100 g.

Ascorbic acid analysis

The analysis was carried out following the method reported by Hung and Yen (2002). 200 ul of the aqueous yogurt extract was reacted with 1,800 ul of solution prepared from 2,6 dichlorophenolindophenol, recording the absorbance at 520 nm, obtaining the amounts of ascorbic acid with the following Equation:

\begin{array}{l} A_{520} = A_{C o n t r o l} - A_{s a m p l e} \end{array}

In which the control absorbance was obtained by the reaction of 200 μl of 0.4% oxalic acid with 1,800 μl of 2,6 dichlorophenolindophenol.

Sensorial analysis

The sensorial evaluation was carried out under the methodology described Senaka Ranadheera et al. (2012) with some modifications, in which regular consumers of yogurt participated, whose frequency of consumption was at least once a week, an evaluation sheet was given to each panelist in order to assess the different treatments. This sheet includes a 5-point hedonic scale (1: I dislike it very much; 2: I dislike it; 3: I neither like it nor dislike it; 4: I like it; 5: I like it a lot).

Results and discussion

pH analysis and soluble solids (°Brix) of Mangifera indica and Myrciaria dubia

The values of the soluble solids content for M. indica and M. dubia were evaluated. Their values have been reported in Table 3.

TABLE 3

Table 3. pH evaluation and sugar content of fruit.

As observed in Table 3, the fruits pH (M. indica and M. dubia) ranged between 2.47 and 4.6, while the sugar content was between 4 and 15%. The pH and sugar content of the fruits are parameters to consider during the yogurts production due to their role in the final product stability, as well as their change to the pH due to their own level of acidity (Parvin et al., 2019). The pH value of mango pulp according to studies carried out on six varieties (Tommy, Kent, Keitt, Dodo, Local and Apple mango), is in the range of 3.33–4.75 (Bekele et al., 2020), while for M. dubia (5.35–6.8) Brix and (2.51–2.54) pH (Castro et al., 2018).

Preparation of yogurt samples using Mangifera indica and Myrciaria dubia

The pH values of the five fruity yogurt preparations ranged from 4.10 to 4.46. These values were slightly lower than those described by Körzendörfer and Hinrichs (2019) who made fermented yogurts with pH values around 4.8 or 5.0 and very close to the values obtained by Lugo-Zarate et al. (2021) with pH between 4.16 and 4.44 by adding cactus pear juice powder (Opuntia ficus-indica). The pH range (4.3–4.7) is usually evident after 3–4 h of fermentation. However, a significant decrease in the pH value occurs between the second and third hours of fermentation due to the concentration of lactic acid due to microbial action (Naibaho et al., 2022). The average pH values should range between 4.33 and 4.83, while the average percentage of lactic acid in yogurt is between 0.77 and 0.92 (Rahmatuzzaman Rana et al., 2021). One of the reasons why the pH presented low values in some treatments is due to the low pH of M. indica (4.6), M. dubia (2.54) and F. vesca (3.42).

Proximate composition of Mangifera indica and Myrciaria dubia yogurts

The proximal composition of the five yogurt treatments is presented in Table 4. Moisture levels were found in the range of 75.3–77.9, total non-dairy solids (22.1–24.6), carbohydrates (17.6–21.0), milk fat (1–2.0), milk protein (2.1–0.2), ash (0.5–0.6) and total energy (95.9–103.9). It can be seen that treatments T3 and T4 have a higher content of total solids (carbohydrates), decreasing their moisture content, and making them a more energetic food (103.9 and 101.4 Kcal/100 g, respectively). A similar case was observed by Diep et al. (2022), that by adding tamarillo powder (Solanum betaceum Cav) at 5, 10 and 15% in yogurts, the moisture content was significantly reduced (78.78–85.79%), compared to the control yogurt (89.72%).

TABLE 4

Table 4. Physicochemical characteristics of Mangifera indica and Myrciaria dubia yogurt.

Ascorbic acid in different samples of yogurt

Table 5 shows the results of the ascorbic acid content of the five yogurt samples produced (four study samples and a control sample).

TABLE 5

Table 5. Ascorbic acid analysis of the yogurts.

The content of ascorbic acid (AA) in the yogurt samples was significantly different between the different samples evaluated (T1: 63.2 mg/100 g; T2: 114.3 mg/100 g; T3: 57.3 mg/100 g; T4: 115.1 and T5: 11.5 mg/100 g). Basically, those samples with content in M. dubia (camu camu) was higher, presented a significant increase in the content of ascorbic acid (treatments 2 and 4), while the variation in the percentage of mango added to the samples did not significantly modify the content of ascorbic acid. The AA content was higher than that found by Khalil et al. (2022) in white sapote pulp (28.25 mg/100 g), the same pulp that was used to make a functional probiotic yogurt. It has been shown that pasteurization in mango juice (90°C for 1 min) reduces 65% of AA (Santhirasegaram et al., 2015). However, a different reaction was observed in M. dubia nectar, heat treatment at 85°C for 60 s, only reduced AA approximately 11.44% (do Amaral Souza et al., 2019). This would explain the little significance of the addition of M. indica pulp in the AA content of the yogurt. For Fernández (2016), one of the most frequent causes for the destruction of ascorbic acid is high temperatures. Also, studies have shown that in citrus fruits, prolonged contact of food with oxygen causes the degradation of AA by oxidation (Agudelo et al., 2020). Fracassetti et al. (2013) showed that M. dubia flour presented interesting values of ascorbic acid from 3.51 g/100 g to 9.04 g/100 g. It was also observed that the highest content of polyphenols was found in the peel. Moreover, Fidelis et al. (2020) reported an increase in phenolic compounds and antioxidant capacity by increasing the concentration of freeze-dried M. dubia seed extract in yogurt. The by-products of this fruit produced yogurt enriched with these bioactive compounds.

Sensory qualities of yogurt samples from Mangifera indica and Myrciaria dubia

The results showed the low consumption of yogurt in the city of Sullana, data shown in Figure 2.

FIGURE 2

Figure 2. Frequency of yogurt consumption.

It is evident that large proportion of evaluators consume yogurt between one and two times during the month (52.78%), 22.22% consume it once during the week; while 19.44% consumed 2 to more times during the week. Those who do not consume yogurt represent 5.56% of the total number. From the above, one can infer the need to increase the consumption of yogurt. This data reflects the difficulty of accessing the product due to its high costs, the limited local supply and other barriers. Toapanta and Arroyo (2020) found that 39% of the surveyed people consume yogurt 3 times a week in the Sierra de Ecuador, because they consider it to be a healthy product. The perception of yogurt influences its consumption Allen Ellen (2012). A study showed that, out of 75 evaluators, 97.33% considered yogurt as a beneficial food for health, and also 98.67% of the evaluators valued the consumption of yogurts with added natural antioxidants of paramount importance Fidelis et al. (2020). In addition, other investigations have revealed that organic and functional yogurts have a higher value and acceptance than conventional yogurt; a trend that increases in the consumer sector with greater knowledge related to diet/health, as well as to aging (Ares et al., 2010; Van Loo et al., 2013; Bimbo et al., 2017). The majority of the evaluators considers yogurt as a snack, that would explain the low consumption of this product found in this investigation.

Organoleptic characteristics of yogurt from Mangifera indica and Myrciaria dubia

The evaluation of sensorial preferences describes the quality that will finally determine the acceptability and the consumption of a certain food (Flores-Mancha et al., 2021), hence the importance of carrying out this study. According to Figure 3, the organoleptic characteristics for the different attributes such as sweetness, acidity, odor, consistency and general appearance show significant differences between the different samples. For the sweetness, the treatment 3 and control were more pleasant while the treatments 2 and 4 were the least pleasant. During the preparations, an attempt was made to standardize the content of the sugars in all cases, however, these results demonstrate that the intense acid taste interferes significantly, masking the sweet flavor in those treatments with greater content in M. dubia (T2 and T4), evidenced by the lowest scores in the sensorial evaluation. This indicates a greater preference for sweeter, less acidic products.

FIGURE 3

Figure 3. Sensorial preferences of yogurt samples.

Regarding the attributes of smell, consistency and appearance in general, no significant differences were found, resulting in the samples being very similar, even with the control treatment.

The perception of consumers regarding the different yogurt treatments can be seen in Figure 3.

Treatment 1: 15% M. indica and 5% M. dubia; Treatment 2: 15% M. indica and 10% M. dubia; Treatment 3: 20% M. indica and 5% M. dubia; Treatment 4: 20% M. indica and 10% M. dubia; Treatment control: 15% F. vesca.

Consumers scored yogurt based on sweetness, acidity, odor, consistency and appearance in general. Treatment 3 was the most balanced sample control and obtained values around 3 points on a scale between 0 and 5 points. Treatment 2 and 4 were the least valued, with the sweetness and the acidity parameters showing the differences between the evaluated treatments.

The differences with respect to sweetness and acidity are related to the addition of fruit pulp, which has an effect on the other attributes evaluated. For Pereira et al. (2021) the texture of the yogurt is influenced by the type of sweetener used, notably the addition of M. indica pulp and phospholigosaccharides. Karnopp et al. (2017) demonstrated that the incorporation of grape juice positively affects the viscosity and consistency of yogurt, while yogurt with grape flour had greater hardness and consistency, having a greater influence on the texture of the comparison of the oligofructose. Sucrose is usually more valued for yogurt making over other sweeteners (Parra Huertas et al., 2016), being able to reduce up to 25% without significantly affecting sweetness (Oliveira et al., 2021).

On the other hand, regarding acidity, in a smooth yogurt, a decrease in this parameter was evidenced as the concentration of aggregates such as chia and raisin puree increased, resulting with 0.5% chia and 15% raisin puree the best score affecting to a lesser extent the acidity, viscosity, firmness and general acceptability of the yogurt (Gonzales and Zevallos, 2015). Similarly, it was shown that M. indica in yogurt formulations substantially improves the flavor during sensory evaluation despite containing stevia (Parra Huertas et al., 2016). In another study, it was shown that the enrichment of fermented milk with fig puree in different proportions (5, 10 and 15%) was sensorially acceptable, despite the fact that the pH decreased (5.34 to 4.43) and the acidity increased (0.48 to 0.77%), in this sense; the addition of fruit at an optimal level improves the sensory quality, physical-chemical and rheological properties of the yogurt (Abd-Eltawab, 2019).

Other parameters are evaluated in sensory studies of yogurt, such as using polymerized whey protein (PWP) was shown to be a potential thickening agent of protein origin that improves the consistency of goat's milk yogurt and other products (Wang et al., 2012). On the other hand, a study by Pingo et al. (2019) showed that some fruits such as aguaymanto (golden berry) or pear subtract value in some cases, concluding in the importance of not exceeding percentages of added fruits.

With this study it was shown that M. dubia has a high amount of ascorbic acid and maintains these properties in the final product (yogurt), being beneficial for health in the prevention of respiratory infections, skin lesions, bleeding gums (Potter and Hotchkiss, 1998; Scott et al., 2001) and especially in wound healing (Levine et al., 1996; Lee et al., 2003). For this reason, future research is recommended to evaluate the incorporation of M. dubia yogurt as a functional product in restaurants and mainly in dairy product businesses.

Amazonian countries like Peru, have an important production of fruits such as M. dubia or Moringa oleifera, their importance has been demonstrated in restructuring the intestinal microbiota, controlling infectious processes and improving immunity (Mehwish et al., 2020, 2021a,b), improvement of inflammations and antiviral qualities (Xiong et al., 2021, 2022) which encourages the development of new research to elucidate the presence of micronutrients and the mechanism of action of these compounds of medical interest. On the other hand, the food industry is interested in knowing the presence of volatile aromatic compounds, the level of biodigestibility and the study of the shelf life for their introduction to the market. Research groups from universities and companies are encouraged to work on new lines of research that value M. indica for its significant sugar content and M. dubia for its high content of ascorbic acid.

Additionally, it is necessary to carry out randomized clinical trials to determine the effectiveness of yogurt using these fruits in the dietary treatment of postoperative patients at the intestinal level (Jia et al., 2018). Recent studies report the importance of the intestinal microbiota in the regulation of the production and signaling of bile acids. According to Halloran and Underwood (2019) several probiotics inhibit the Toll-like receptor 2.4 (TLR2 and TLR4) and stimulate the action of inflammatory mediators, improving intestinal function by strengthening the mucus and the union of enterocytes in the layer of the intestine, therefore the consumption of yogurt is recommended in postoperative patients.

Conclusions

The ascorbic acid content of the different M. indica and M. dubia yogurt treatments remained with significantly high values (T1: 63.2 mg/100 g; T2: 114.3 mg/100 g; T3: 57.3 mg/100 g; T4: 115.1) unlike the control treatment (TC: 11.5 mg/100 g). However, the sensorial evaluation showed a significant influence in those treatments with 10% of M. dubia, decreasing its level of acceptance due to its acid taste, being better valued those treatments that contained 5% of this fruit with respect to the total mass of the yogurt, while the addition of M. indica did not significantly influence organoleptic parameters, having used up to 20% of the total mass of yogurt.

Data availability statement

The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.

Ethics statement

Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. The patients/participants provided their written informed consent to participate in this study.

Author contributions

JB contributed to the conception and design of the study, reviewed the scientific literature, participated in the laboratory experiments, analyzed the data, and wrote the manuscript. JV-M contributed to the laboratory experiments and field work during the sensory analysis, analyzed the data, reviewed the scientific literature, and wrote the manuscript. LM-Q contributed in the review of the scientific literature, collaborated during the sensory analysis, supervised the data analysis, wrote and corrected the manuscript, and sought funds to finance the study. LE-E contributed to the conception, design and planning of the study, supervised the field and laboratory work and analyzed the data, wrote and revised the manuscript, and sought funds to finance the study. All authors contributed to the article and approved the submitted version.

Funding

This research received financial support from the Universidad Nacional de Frontera, Peru. Resolution N° 069-2020-CO and Agreement N° 002-2020-UNF.

Acknowledgments

We thank the volunteers who participated in the sensory analysis and the laboratory staff of the Universidad Nacional de Frontera.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher's note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

References

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