Studies on physical, chemical and microbial properties of sweet potato chips (Ipomoea batatas L.)

The present investigation was carried out to study physicochemical composition of Sweet Potato Chips. The different physicochemical properties of Sweet Potato Chips viz., moisture, fat, protein, carbohydrates, ash and were determined. Result obtained for proximate composition of Sweet Potato Chips revealed that moisture content was 4.0%, fat 27.5%, protein 4.3%, carbohydrates 57.3%, crude fibre 4.85%, and ash 3.0%. Physical composition shown that the shape was circular, colour was golden yellow to light brown, diameter 4.2 cm, thickness 0.1cm, weight 0.16 gm, circumference 13.29 cm and hardness measured was 20 N. The nutritional value of Sweet Potato Chips can have better suitability in value addition of food products. Sweet potatoes are rich in dietary fibre, vitamins, minerals, and antioxidants, making them a healthier choice for consumers seeking both taste and nutrition.

Illustrations explain the paper; charts are replotted from the paper's own table values.

AI-generated illustration

↗ Enlarge

Analysis FrameworkClose ×

AI-generated conceptual illustration (sweet potato chips (Ipomoea batatas L.)). It explains the idea and does not show study data.

Open full-size image ↗

Replotted from source data

↗ Enlarge

Mean Values*: Moisture vs Crude Fat vs Protein vs Carbohydrates vs Crude FibreClose ×

Replotted from Table 2 (page 2) of the original paper. Every bar is the paper's own table value.

Open full-size image ↗

Introduction

Sweet potato (Ipomoea batatas L.) is a tuber crop belonging to the family Convolvulaceae, widely cultivated in tropical and subtropical regions of the world such as India, China, and several parts of Africa and America (Woolfe, 1992) [13] . It is an important root vegetable valued for its high nutritional and economic significance. Sweet potato tubers are rich in carbohydrates, dietary fibre, vitamins (A, C, and B6), minerals such as calcium and iron, and natural antioxidants (Burri, 2011) [1] . The presence of beta-carotene provides the characteristic orange or yellow color and contributes to its role in improving vision and enhancing immunity (Laurie et al., 2012) [4] . In India, sweet potato is grown mainly in the states of Odisha, Uttar Pradesh, Bihar, and Maharashtra (Nedunchezhiyan et al., 2012) [5] . Traditionally, it is consumed in boiled, roasted, or baked form, but in recent years, there has been increasing interest in developing value-added products to enhance its utilization and market potential. Among these, sweet potato chips have emerged as a promising snack product due to their unique natural sweetness, crisp texture, and high nutritional content (Shah et al., 2016) [9] . Sweet potato chips serve as a healthier alternative to conventional potato chips as they are rich in fibre, vitamins, and antioxidants, and contain relatively low fat when prepared under optimized frying or baking conditions (Ellong et al., 2014) [2] . Moreover, the use of sweet potato in snack production helps in diversifying food products and reducing post-harvest losses of the crop (Padmaja, 2009) [7] . The growing demand for nutritious and convenient snack foods provides a strong basis for the development and commercialization of sweet potato chips as a functional and appealing product for health-conscious consumers (Singh et al., 2015) [10] .

Materials and Methods

The study was conducted in the Department of Food Plant Operation, Food Chemistry and Nutrition, Food Microbiology at K. K. Wagh College of Food Technology, affiliated with Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra. The research focused on the development of a novel ready-to-eat snack, sweet potato chips, prepared using sweet potato, sunflower, spices seasoning.

All raw materials were purchased from local market of Nashik and were analysed for the nutrients namely moisture, protein, fat, ash, crude fibre carbohydrate content. Fresh, mature sweet potatoes (Ipomoea batatas L.) of uniform size and good quality were bought from the local market (Nedunchezhiyan et al., 2012) [5] . The tubers were washed properly under clean running water to remove dirt and soil. They were then peeled using a stainless-steel knife and sliced into thin, even pieces about 2-3 mm thick with the help of a slicer (Padmaja, 2009) [7] .

Proximate Analysis

Different chemical properties of samples were analysed for moisture content, ash, fat, protein and total carbohydrate. All the determinations were done in triplicate and the results were expressed as the average value. (Talpade et al., 2018) [11] .

Moisture Content

Moisture content was determined adopting (AOAC, 2005) method as following: Fat (AOAC, 2005) Method using Soxhlet apparatus was used to determined crude fat content of the sample. The percent of crude fat was expressed as follows:

Protein: Protein content was determined using (AOAC, 2005) method. Percentage of nitrogen and protein calculated by the following equation:

Where, Ts = Titre volume of the sample (ml), TB = Titre volume of Blank (ml), 0.014= M eq. of N2. % Protein = Nitrogen × 6.25

Total carbohydrate

Total carbohydrate content of the samples were determined as total carbohydrate by difference, that is by subtracting the measured protein, fat, ash and moisture from 100 phenol sulphuric acid method as given by (AOAC, 2005).

Ash

Drying the sample at 100 0 C and churned over an electric heater. It was then ashes in muffle furnace at 550 0 C for 5 hrs. It was calculated using the following formula:

Where, AW = Weight of Ash and IW= Initial weight of dry matter

Results and Discussion Physical properties of Sweet Potato Chips

Various physical properties of Sweet Potato Chips were determined and results obtained are presented in Table 1. The data given in Table 1 shows the different physical characteristics of sweet potato chips. Colour plays an important role in deciding how appealing a product looks. The colour of sweet potato chips was observed to be light yellow to orange with a thin brownish skin and circular in shape. Each chip slice weighed around 0.5 g, with an average diameter of 5.4 cm, circumference of 16.96 cm, and a slice thickness of 0.2 cm. These results were quite similar to those reported by Falade and Omojola (2010) [3] and Shittu et al. (2015) for sweet potato chips.

Parameters	Result	Method
Shape & Size	Circular	Visual Observation
Color	Light yellow to orange Thin brownish skin	Visual Observation
Weight	0.5 g per slice	Digital Weighing Balance
Diameter	5.4 cm	Vernier Caliper
Slice Thickness	0.2 cm	Vernier Caliper
Circumference	16.96 cm	Circumference = π x Diameter

Table text extracted from the original PDF; superscript letters are shown inline. The original table image is below.

View original table image

↗ Enlarge

Table 1Close ×

Physical Parameters of Sweet Potato Chips

Open full-size image ↗

Original paper tableSource PDF · page 2 ↗

Graph 1: Graphical Representation of Proximate analysis

The chemical composition of the sample was analysed for major nutritional constituents, including moisture, fat, protein, carbohydrates, ash, and crude fibre. Revealed the moisture content was 4.0%, fat 27.5%, protein 4.3%, carbohydrates 57.3%, crude fibre 48.5%, and ash 3.0%.

Conclusion

The present study on sweet potato chips revealed that the product possesses desirable physical, chemical, and sensory qualities, making it a promising value-added snack. The chips were found to have an appealing light yellow to orange colour with a crisp texture and pleasant taste. Proximate analysis showed a good balance of nutrients, with moderate fat and carbohydrate content, along with appreciable amounts of protein and fibre. The microbial analysis indicated that the chips were within safe consumption limits during the storage period. These results suggest that sweet potato chips can serve as a nutritious and convenient snack alternative to conventional potato chips. Hence, the development and promotion of such products can enhance the utilization of sweet potatoes and contribute to food diversification and nutritional security.

Figures and tables from the paper

Parameters	Mean Values*	SE± @5%	CD± @5%	Method Reference
Moisture	4.0%	0.058	0.25	AOAC (2000), IS:1155
Crude Fat	27.5%	0.058	0.25	AOAC (2000), IS:1011
Protein	4.3%	0.058	0.25	AOAC (2000), IS:7219
Carbohydrates	57.3%	0.058	0.25	AOAC (2000), IS:1656
Crude Fibre	4.85%	0.058	0.25	AOAC (2000), IS:10226
Ash Content	3.0%	0.058	0.25	AOAC (2000), IS:13654

Table text extracted from the original PDF; superscript letters are shown inline. The original table image is below.

View original table image

↗ Enlarge

Table 2Close ×

Proximate composition of Sweet Potato Chips

Open full-size image ↗

Original paper tableSource PDF · page 2 ↗

Storage Days	TPC (CFU/g))	Desirable Limits**
1	3.1 × 10²	TPC 5.0 × 10⁴ CFU/g
4	3.5 × 10²
8	3.9 × 10²
12	4.5 × 10²
16	5.1 × 10²
20	5.9 × 10²
24	7.0 × 10²

Table text extracted from the original PDF; superscript letters are shown inline. The original table image is below.

View original table image

↗ Enlarge

Table 3Close ×

Microbial analysis of sweet potato chips

Open full-size image ↗

Original paper tableSource PDF · page 3 ↗

1. Burri BJ. Evaluating sweet potato as an intervention food to prevent vitamin A deficiency. Compr Rev Food Sci Food Saf. 2011;10(2):118-130.
2. Ellong EN, Billard C, Adenet S, Rochefort K. Comparison of physicochemical, organoleptic, and nutritional characteristics of ten sweet potato (Ipomoea batatas L.) varieties. Food Nutr Sci. 2014;5(2):196-211.
3. Falade KO, Omojola BS. Effect of processing methods on physical, chemical, rheological, and sensory properties of sweet potato chips. J Food Process Preserv. 2010;34(1):16-28.
4. Laurie SM, Faber M, Adebola P, Belete A. Biofortification of sweet potato for food and nutrition security in South Africa. Food Res Int. 2012;49(1):2430.
5. Nedunchezhiyan M, Byju G, Jata SK. Sweet potato agronomy. Fruit Veg Cereal Sci Biotechnol. 2012;6(Special Issue 1):1-10.
6. Oluwole OB, Karim RO, Balogun SA. Production and quality evaluation of sweet potato chips and flour. Niger Food J. 2013;31(2):91-96.
7. Padmaja G. Uses and nutritional data of sweet potato. In: The Sweet Potato. Dordrecht: Springer; 2009. p. 301-331.
8. Ravindran V, Sivakanesan R. Total and phytate phosphorus contents of tropical tuber and root crops. J Food Compos Anal. 1995;8(3):328-336.
9. Shah FU, Sharif MK, Bashir S, Iqbal Z. Development and quality evaluation of sweet potato chips. Pak J Food Sci. 2016;26(4):213-220.
10. Singh S, Riar CS, Saxena DC. Effect of incorporating sweet potato flour to wheat flour on quality characteristics of cookies. Food Nutr Sci. 2015;6(5):447-456.
11. Talpade K, Deshmukh S, Patil R, Jadhav P. Study on physicochemical properties of sweet potato-based products. Int J Curr Microbiol Appl Sci. 2018;7(5):3352-3360.
12. Teye E, Quartey ET. Physicochemical and sensory evaluation of vacuum-fried sweet potato chips. Int J Food Sci Nutr Eng. 2018;8(3):49-56.
13. Woolfe JA. Sweet Potato: An Untapped Food Resource. Cambridge: Cambridge University Press; 1992. p. 1643.