Nutritional composition of monk fruit (Siraitia grosvenorii) as a candidate yogurt sweetener

Yogurt is a dairy product considered a healthy food due to its nutritional and health benefits. To add flavor to the yogurt, sucrose is added, which causes an increase in calories and makes it unsafe for diabetics. Monk fruit is the fruit of the Chinese plant Luo Han Guo (Siraitia grosvenorii). Monk fruit is known for its sweet flavor. This study aimed to determine the nutritional compounds of monk fruit. This study will focus on characterizing the biochemical composition of monk fruit with the objects of peel (T1), flesh (T2), and whole fruit (T3). Each object consists of 6 replications with parameters: water content (%), ash (%), fat (%), protein (%), carbohydrate (%), and the percentage of total sugar (%). The data were analyzed using a one-way ANOVA. The Duncan test was followed when performing the multiple comparisons. The results obtained showed nonsignificant differences (P>0.05) in total sugar (%). The flesh contains the least water and ash (P<0.05) compared to the peel and whole fruit; the peel contains the lowest protein and the highest carbohydrate (P<0.05), the whole fruit contains the lowest fat; but total sugar (%) is the highest compared to the peel and flesh (P>0.05). Based on the nutritional composition of this study, it is recommended that the best part of monk fruit as a candidate natural sweetener for yogurt is the flesh. Although total sugar (%) was not significantly different from other monk fruit parts, the flesh had the highest protein (P<0.05) and the lowest fat (P<0.05), which is equivalent to low calories. The flesh of monk fruit as a low-calorie sugar alternative can be used in functional foods that have many health benefits, so it is a great candidate for yogurt sweetener.


Introduction
Monk fruit is the regional name for Siraitia grosvenorii, which is also popularly known as monk fruit, and it contains a wide array of bioactive compounds for health [1].It has been consumed by Asian people as a traditional medicine since the 13th century [2].The fruit has historically been used as a food sweetener and medicine [3].Flavones, proteins, saccharides, vitamins, and volatile oils are all present in them, and triterpene glycosides, commonly known as mogrosides, have sweet properties [4].Monk fruit is a native fruit of China and has high biological effects and a sweet taste.The mogrosides contained in monk fruit are thought to be the cause of monk fruit's sweetening properties [5].Triterpenoids, essential oils, amino acids, and polysaccharide components are all present in monk fruit, whereas triterpenoids are one of the main biologically active compounds [6].
Additionally, it has been claimed that monk fruit elicits several biological activities, such as hypoglycemic response, anti-oxidative effects, and qualities that prevent tissue damage, allergy, and cancer [4].The potential of monk fruit as a biodegradable sweetener in culinary products encourages the investigation of monk fruit safety, especially the nutraceutical potential of monk fruit [7].It is safe and has an impact on the organoleptic properties of prepared food products.The popularity of monk fruit expanded in global markets, including the food and beverage industries, due to the growing desire for natural, non-nutritive sweeteners.Replacement of sucrose sweetener with non-caloric sweetener may help control glucose levels [8].Monk fruit has a wonderful prospect for use as a low-calorie sugar substitute.This study focuses on the biochemical content of monk fruit.The urgency of this research is to verify the biochemical content and optimal sugar content to be applied in the development of sugar-free, low-calorie foods, in this case, yogurt functional foods, whose yogurt consumption improves antioxidant status.The goal of this study is to demonstrate the biological properties of its low-calorie natural sweetener that are linked to its bioactive ingredients in peel, fruit, and whole fruit.

Preparation samples
The first stage is the physical selection of monk fruit.Identify a monk fruit by selecting the characteristics of a fruit whose skin color is bright brown, and whose peel is smooth and clean.The peels were washed and allowed to dry at room temperature.Monk fruit is peeled, the skin obtained is stored as peel, the fruit and seeds are stored as flesh, and the whole fruit is the whole fruit with the skin.The yield was recorded, and then the monk fruit was separated between the peel, the flesh, and the whole fruit was dried at 50 °C, and then ground to obtain a fine powder.

Treatments
The treatments are based on the parts of the monk fruit: T1 = peels, T2 = flesh, and T3 = the whole fruit.Each treatment was repeated six times, so there were eighteen samples.

Methods of analysis 2.3.1. Water content.
Dry the porcelain disk in a 105⁰C oven for 3 hours.Weigh the weight of the cup (W1).After weighing the sample, transfer it to the porcelain cup (W2).Dry for three hours at 105 in the oven.In a desiccator, cool (15 minutes).Weigh the rate of samples and repeat until there is a constant weight (W3).The method was obtained by SNI 01-2891-1992.The water content was determined according to the equation below: Water content (%) = (W2-W1)/(W3-W1) x 100% (1)

Protein.
Weigh the 0.51 g sample and put it into a 100 mL Kjeldhal flask.Add 25 mL of concentrated H2SO4 and 2 g of selen mixture.Heat the mixture over a burner flame or electric heater until it turns clear and somewhat green (2 hours).After letting it cool, dilute and fill a 100 mL volumetric flask with the line.5 mL of the solution should be pipetted and added to the distiller.Add a few drops of PP indicator and 5 milliliters of 30% NaOH.Use 10 mL of a 2 percent boric acid solution that has been combined with the indicator as a reservoir and distill for 10 minutes.Use pure water to rinse the cooling tip.Use a 0.01 N HCl solution to titrate.Carry out the blank determination.The number 14,007 represents the atomic weight of nitrogen and 6.25 is the conversion factor.The method was obtained by SNI 01-2891-1992.For one hour, dry in the oven at a temperature of no more than 80 (W1).Place into a dry fat flask with a given weight and use a soxhlet tool to assemble.For six hours, distill using hexane or a similar fat solvent.In a drying oven set at 6, distill the hexane and dry the fat flask.Weigh after cooling.Continue doing this until a steady weight is achieved (W2).The technique was acquired through SNI 01-2891-1992.The following equation was used to calculate the fat content.

Total sugar (%)
.Weigh 1 gram of the sample and add 25 mL of 80% ethanol.Transfer the supernatant into a 100 mL volumetric flask after stirring for ten minutes.Repeat steps 2-3 until the filtrate obtained is exactly 100 mL.Evaporate the ethanol in a water bath or hotplate with a beaker glass, add 1 gram of CaCO3 and 100 mL of distilled water, then heat for 30 minutes (under boiling conditions), cool down, add saturated Pb-acetate and K-oxalate as much as 5 drops each, then filter, and measure to 100 mL using a volumetric flask.Add up to 25 mL of the second sample solution.added 5 mL of 6.76 percent HCl and 10 mL of distilled water, then heated in a water bath at 60 for three minutes while shaking, and left in the water bath for 7 minutes.

Data Analysis.
A one-way ANOVA was used to evaluate the data, and if it revealed a significant effect, Duncan's comparison test using SPSS version 22.

Results and discussion
Nutrient analysis provides nutritional composition information to verify the quality of the tested sample, such as water content, protein, lipid, ash, and carbohydrate content [9].The nutritional composition data of peels, fruit, and whole fruit are listed in Table 1.
Water, ash, fat, protein, carbohydrates, and fiber in the peel are the macronutrients that are the most abundant in monk fruit peels.Even in the driest foods, there is still water content [10].Peels contain a wide variety of secondary compounds and are valuable sources of molasses, pectin, and limonene [11], which constitute 50% of the fruit's initial weight.Peel is a waste material from various fruits and vegetables [12].Water content in peel showed a higher (P<0.05)than in fruit and whole fruit; this is in the opinion of [13] [14].Peels have a high water content, which contributes to their great perishability.Protein content in flesh is the highest (P<0.05) at 11.46%, while whole fruit is also higher (P<0.05) at 10.77% compared to peels.This is higher than the opinion [15] that the protein content of fresh monk fruit is between 7.1 and 7.8%.The protein content in peels is lower, according to [16] [10].Fruit-derived fiber is of higher quality than other types of fiber because it has a higher percentage of soluble fiber and a lower phytic acid and caloric value.
Fat is a source of energy and is used as a source of carbohydrates if the carbohydrate content is reduced [17].Fat content is positively correlated with the number of calories; the highest fat content is in the peel, followed by the whole fruit, and the lowest is in the flesh (P<0.05), which indicates the lowest calorie content (P<0.05)monk fruit is the flesh part.Similar findings report that the flesh of monk fruit has a lower calorific value than sucrose [18].
Ash refers to solid components, where a good source of several minerals is indicated by 5 to 6% [19].Similar findings were also observed in a study that a reported that higher ash content indicates a better source of minerals [20].Total ash was highest in the whole fruit, followed by peel, and lowest in flesh (P<0.05).
Total carbohydrate is highest in peel (P<0.05).Peels contain crude fiber in the form of lignin and cellulose.Cellulose is a polysaccharide that, when hydrolyzed, will produce glucose monomers and some cellobiose.The nature of cellulose is that it is insoluble in water and very easy to absorb [21].
The total sugar in milligrams in this study was not significantly different as well, and the percentage of total sugar in parts of monk fruit was not significantly different either, but the results in this study were much higher than the report [15], which stated that the total sugar was 25.17 to 38.31%.

Conclusion
Based on the study's findings, flesh is the part of monk fruit that has the best nutritional content because it contains more protein and less fat than peel and whole fruit, thus indicating the lowest calorie content.The flesh of monk fruit showed the most optimized parameters as a natural sweetener candidate for yogurt.
titration volume-blank)*normality of HCl*14.2.3.3.Fat.Weigh out 2 grams of the sample (W) and place it into a known-weight filter paper sleeve.

Table 1
Biochemical composition of peel, flesh, and whole fruit of Monk fruit