The effect of purple sweet potato flour (Ipomoea batatas L) as substitution on anthocyanins content and antioxidant capacity of snow white’s ball cookies

This research investigates the impact of substituting wheat flour againts purple sweet potato flour (Ipomoea batatas L.) on the anthocyanins content and antioxidant capacity of Snow White’s Ball Cookies. Anthocyanins are natural vibrant red, purple, and blue pigments contained in many foods; including purple sweet potato. Anthocyanins are part of a larger group of compounds called flavonoids, which have antioxidant properties and are associated with several potential health benefits. Antioxidants are known for their role in mitigating oxidative stress and promoting health. Purple sweet potatoes are esteemed for their rich antioxidant content, primarily attributed to the presence of anthocyanins. This study aims to determine whether including purple sweet potato flour (PSPF) enhances the antioxidant properties of these cookies. The method used in this study is a completely randomized design experiment (CRD). There are four treatments: substitution of 25%, 50%, 75%, and 100%. The results of this study indicate that 100% (Formula E) substitution of purple sweet potato flour has the lowest antioxidant capacity of 85.04 ppm and higher anthocyanins content of 5.30 (mg/100g). So, it is proven that the antioxidant content in the form of anthocyanins in snow white ball cookies is high.


Introduction
Purple sweet potato is a potential food commodity in Malang, besides being consumed by local people, tourists usually also buy purple sweet potatoes as food souvenirs [1].The craze of people and tourists in consuming purple sweet potatoes is due to the delicious taste of purple sweet potatoes, it is also believed to provide health benefits [2].The problem is that farmers often harvest more than they sell, so they often lose money due to low selling prices.This is due to the lack of knowledge of processing sweet potatoes into various products that have a higher selling value [3].One solution that can be done is to make purple sweet potato flour (PSPF) [4].PSPF contains macronutrients, micronutrients and bioactive components that are beneficial for the body, it is rich in protein and minerals, low in fat, and high in anthocyanin [5].
Based on the results of research on purple sweet potato flattening slightly reduces the anthocyanin content, but the level of anthocyanins contained in PSPF is still higher compared to when processed in other ways [6].Anthocyanins are a group of naturally occurring pigments found in various fruits, vegetables, and plants, they are responsible for the purple, red, and blue colors seen in many foods.Anthocyanins are part of a larger group of compounds called flavonoids, which have antioxidant properties and are associated with several potential health benefits, its play a pivotal role in protecting cells from oxidative damage, thereby contributing to overall health and well-being [7].Recently, research interest in incorporating nutrient-rich ingredients into food products to improve their nutritional composition has been increasing [8,9,10].
PSPF can be an ingredient that replaces wheat flour in baking products [11], However, until now the use of PSPF in food processing is still very limited [12].This research tries to use PSPF as a substitute for wheat flour in making snow white ball cookies.This research was conducted to determine the antioxidant levels in purple sweet potato substitute cookies, so that it is scientifically proven to contain more antioxidants than cookies made from wheat flour, and can be considered as food souvenirs especially in Malang that have healthful benefits.Scientific proof is important, because nowadays tourists when buying food souvenirs also consider buying products that have health benefits [13].

Materials
The ingredients used in making the research product (Snow white ball cookies) consisted of butter, margarine, icing sugar, egg yolk, medium protein wheat flour, cornstarch (maizena), milk powder, cheddar cheese, and PSPF (Table 1).The ingredients were obtained by purchasing at a cake ingredient store in Malang.The PSPF used in this study was purchased from a purple sweet potato flour producer in Malang.The equipment used was a cookies making tool including scale, bowl, mixing bowl, mixer, spatula, baking sheet and oven.The cookies are made using the creaming method, which is by beating butter, margarine, egg yolk, and icing sugar that have been mixed in a mixing bowl then stir until well mixed using a mixer until it has a cream-like texture, then add cornstarch, powder or maizena, milk powder, flour, and cheddar cheese, stirring using a spatula, until well mixed, after that print it with a round shape, then arrange it on a baking sheet, then baked until cooked at 150 o C for 25-30 minutes.

2.2.Methods
This research is an experimental study and used CRD (completely randomized design) with two repetitions design.In Table 2  This research was carried out from May to August 2023.This research product develop involves pastry shop as partners, this research product is made in their kitchen, and after done it is packed and then sent to be tested for their anthocyanin content and antioxidant capacity at the chemistry laboratory of the University of Muhammadiyah Malang.Analysis pH differential method was used to measure the Anthocyanins content [14], while DPPH was used to determine the antioxidant capacity using DPPH [15].

Results and discussion
Based on data analysis, the results of anthocyanin content and antioxidant capacity contained in Snow White Ball Cookies, are displayed in Table 3 below.

Anthocyanin content
Based on the analysis results contained in Table 3, it shows that compared to the product made from the control formula which does not contain anthocyanins at all, the substitution of 25% purple sweet potato flour (Formula B) has a significant effect on the addition of anthocyanin content value of 3.55 mg/100g.This shows and proves that the treatment of substituting wheat flour with purple sweet potato flour (PSPF) in the manufacture of snow white ball cookies has an effect on the addition of anthocyanin content in cookies.Furthermore, based on the results in Table 3, there is an effect where the higher the percentage of replacement of wheat flour with PSPF, the higher the anthocyanin content.The highest anthocyanin content was found in the treatment of 100% substitution (Formula E) of PSPF for wheat flour with a value of 5.30 (mg/100g).
Anthocyanins in purple sweet potatoes are higher than other types of sweet potatoes [6].Anthocyanins are natural pigments that cause reddish, purple, and blue colors [5], anthocyanins have the ability as antimutagenic and anticarcinogenic so that they can combat oxidative stress in the body that causes cancer.Consuming foods or beverages containing anthocyanins can reduce the risk of chronic diseases such as cancer, and degenerative diseases [16] such as heart disease and diabetes [17].
Functional foods containing anthocyanins are good for heart health, the higher the intake dose of foods with high anthocyanin content can reduce total blood cholesterol levels, namely Low Density Lipoprotein (LDL) levels and triglyceride levels, but have no effect on High Density Lipoprotein (HDL) levels and the ratio of total choles-terol to HDL [14].Research on diabetic 4 patients shows that anthocyanin consumption has an effect on increasing the body's ability to secrete the hormone insulin, and treating insulin resistance [18].This means that consumption of foods or drinks containing anthocyanins helps the body produce and respond to insulin better, so that blood sugar in the body of diabetics is well regulated and there is no significant spike in blood sugar which is fatal to their health condition [17].

Antioxidant capacity
Table 3 shows the results of antioxidant capacity analysis of Snow White Ball Cookies substituted with purple sweet potato.The results show that PSPF substitution has an effect on antioxidant capacity, where there is a significant difference between products that do not contain PSPF at all (Formula A) and products that contain PSPF (Formula B, C, D, E).The higher the percentage of PSPF substitution to wheat flour, the lower the amount of antioxidant capacity/IC50 (ppm), which means the higher the antioxidant activity.This confirms the statement in previous research [19] about PSPF substitution in bread making, the result is that the level of PSPF substitution affects the antioxidant activity of bread where the higher the percentage of substitution, the higher the antioxidant activity.
Antioxidant capacity is an indicator of the amount of antioxidants contained in food, the increase in antioxidant capacity value is in line with the increase in PSPF concentration in the product, this is because PSPF contains high amounts of anthocyanin pigments [20].Several studies have proven that consumption of foods containing antioxidants provides health benefits for the body, it is because antioxidants have the ability to counteract free radicals.Free radicals that are not handled properly in the body trigger degenerative diseases and cancer [21].
This research contributes to the Sustainable Development Goals (SDG) especially goal number 3 about Good Health and Well-being.The development of foods high in antioxidants is beneficial, consumption of foods high in antioxidants can have a good impact on health and prevent non communicable degenerative diseases [22,23,24].

Conclusion
The substitution of PSPF in cookies has an effect on increasing the anthocyanin content and decreasing the antioxidant capacity of snow white ball cookies.Formula E, which is substituted 100% by PSPF, has proven to have a higher anthocyanin content and the lowest antioxidant capacity, which means that cookies contain high antioxidants.With these results, it can be claimed that the product of this research contains antioxidants that are useful for health, and can be defined as a healthy food souvenir.For suggestion, further research is needed to explore the effects of different cooking methods and baking conditions on anthocyanin retention, cookies quality and customer acceptability.

Table 1 .
Formula of snow white ball cookies below can be seen the design of this study.

Table 3 .
Analysis results anthocyanin content and antioxidant capacity in snow white ball cookies