Physico-chemical evaluation of tomato powder

Introduction

Tomatoes (Solanum lycopersicum), members of the nightshade family (Solanaceae), are botanically classified as fruits but are commonly treated as vegetables in culinary contexts. They are cultivated worldwide and hold significant agricultural importance. In India, tomatoes rank third in prominence after potatoes and onions, whereas globally, they are second only to potatoes (Al-Amri, 2013) [1] . Although commonly consumed fresh, processed tomato products-such as pulp, puree, paste, sauce, juice, powder, and peeled tomatoes-make up over 80% of consumption. Tomato powder, in particular, is widely utilized in various products, including soups, instant sauce mixes, ketchup, traditional dishes like sambhar and rasam, baked goods, health foods, baby food, chocolates, and snacks (Temitope et al., 2009) [12] . Drying is a traditional and easiest method of food preservation. It reduces moisture content, thus preventing spoilage by microorganisms, enzymes, and chemical reactions. This process extends shelf life and enables long-distance distribution (Nishizono et al., 2023) [8] . Tomatoes are rich in carotenoids, including lycopene and β-carotene, which provide numerous health benefits (Srivastava & Kulshreshtha, 2013) [11] . Their chemical makeup is influenced by factors such as variety, ripeness, and growing conditions (García-Valverde et al., 2013) [4] . Regular consumption of fresh or processed tomatoes has been linked to reduced risks of inflammation, cancer, cardiovascular diseases, and obesity, as well as enhanced protection against oxidative DNA damage (Raiola et al., 2014) [9] . Tomatoes also offer various health benefits, such as lowering cholesterol, improving vision, supporting digestive health, reducing hypertension, managing diabetes, protecting skin, and preventing urinary tract infections and gallstones. Lycopene is commonly used in cosmetics, pharmaceuticals, and as a natural food colorant (Kumar et al., 2012) [6] . This versatile fruit not only plays a vital role in culinary traditions but also contributes significantly to health and industrial applications.

Materials and Methods

Present investigation was carried out in the Laboratory of Department of Food Science, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, 208002 (UP). Required analysis in this study was conducted at the Regional Food Research & Analysis Centre (RFRAC), Department of Horticulture & Food Processing (UP), Udyan Bhavan Campus,2 Sapru Marg Lucknow 226001.

Duration of the study

The present study was conducted from October 2020 to August 2021.

Procurement of raw material

For carrying out experiments, fully ripened tomato of AzadT6 and Angoorlata varieties were procured from the Department of Vegetable Science of C.S.A. University of Agriculture & Technology, Kanpur in the month of February.

Physical properties of tomatoes

The physical characteristics of tomatoes, including colour, size, and shape, were recorded through visual observation. Locule numbers are counted by cutting ten randomly selected fruits transversely, while pericarp thickness is measured using vernier callipers in triplicate. The weight of ten randomly selected fruits is determined using an electronic weighing balance, and the average weight is calculated. The weight of pulp is measured from 1 kg of tomatoes using both manual and electronic methods. Similarly, the weight of wastage, which includes peel and seeds, is recorded, and the Waste Index is calculated by expressing the waste materials as a percentage. By using formula: Weight of waste portion = weight of peel + weight of seeds. The percentage of edible mass is determined using the formula: Edible mass (%) = 100 -Waste index (%).

Preparation of tomato powder

Tomatoes were weighed, washed thoroughly under running tap water to remove dirt and soil, and drain out excess water, sorted, then sliced to 5-7 mm thickness slices using knife prior to pretreatment process. The slices were kept in a stainless-steel sieve placed over a pan containing boiling water and blanched for 20 seconds. Blanching loosened the skin of tomato and easily removed. Tomato slices were dried from each variety (Angoorlata and Azad T6) of tomato. Slices were placed uniformly in a thin layer onto the stainless-steel trays of size 15×20mm and dried in hot air oven at temperature 65 ºC. Observations were recorded in triplicates. The dried tomato slices were then powdered in a grinder jar.

Proximate Analysis of Tomato Powder

Proximate analysis of tomato powder was done at RFRAC laboratory, Lucknow, U.P. (AOAC 2000). Samples were analysed in triplicates and results are expressed on dry weight basis.

Statistical Analysis

Mean, standard deviation (SD) and standard error± (SD) were used to analyse the data. Considering the confidence level of 95% the difference between the mean values considered to be significant at p< 0.05.

Results and Discussion Physical characteristics of tomato varieties

Visual observations highlighted differences in the colour, size, and shape of the two tomato varieties. Angoorlata was oval in shape with a yellowish-red hue, while AzadT6 had a spherical shape and a deep red colour, findings similar to those reported by Gupta et al. (2011) [5] . Angoorlata was smaller in size compared to AzadT6, with fruit diameters measured at 4×5 cm for Angoorlata (classified as small) and 5×5 cm for AzadT6 (classified as medium). The locule numbers ranged from 2 to 3 in Angoorlata and 3 to 4 in AzadT6, showing a positive correlation between fruit size and locule number, as also noted by Thakur and Kaushal (1995) [13] . The fruit weights of the varieties ranged from 48 grams (maximum for Angoorlata) to 65 grams (maximum for AzadT6), with a positive correlation observed between the two varieties. The pericarp thickness was measured at 0.018 cm for Angoorlata and 0.023 cm for AzadT6. AzadT6 exhibited higher flesh content compared to Angoorlata, which correlated positively with pericarp thickness and fruit weight. However, Angoorlata had relatively higher seed content than AzadT6 (Table 1). of Angoorlata was found to be higher than AzadT6 Similar result was observed by (Bindu et al., 2016) [3] they found that tomato dried in hot air oven had low moisture and ash

International Journal of Agriculture and Food Science https://www.agriculturaljournals.com content than any other drying method. They also reported that, difference in moisture and ash content by different drying methods was significantly affected by tomato varieties. The protein content was 7.07 and 7.36 in Angoorlata and AzadT6 respectively. Total solid content and crude fibre was found to be higher in powder of AzadT6 tomato compared to Angoorlata. There was significant difference between total solids content and crude fibre in between the varieties of tomato. Mozumdzr et al.,2012 reported that the crude fiber content was higher in hybrid tomato varieties than commercial tomatoes (Table -2)

Lycopene and beta-carotene content in Tomato powder

The importance of tomatoes in human diet is due to presence of lycopene. Lycopene may be considered as a valuable quality attribute of tomatoes. 80-90% of the total carotenoids are present in the tomatoes are in the form of lycopene which add value to finished products. Lycopene and beta carotene content of the tomato powder is presented in table 3 and Fig1.

Conclusion

Drying tomatoes is an effective method to extend their shelf life, reducing waste and enabling their use in a variety of products such as soups, sauces, and nutritional supplements. Additionally, it improves the bioavailability of lycopene, a powerful antioxidant associated with a lower risk of several diseases, including certain cancers and cardiovascular issues. Tomato powder, in particular, is highly versatile and has widespread applications within the food industry.

Converting fresh tomatoes into powder simplifies storage and transportation, minimizing spoilage and waste. This also helps stabilize the tomato market by ensuring a consistent supply of tomato-based products throughout the year, irrespective of seasonal harvests. The research highlights the significance of choosing the appropriate tomato variety to achieve superior tomato powder. By optimizing these factors, it is possible to produce a product that maintains the highest nutritional and physical qualities of fresh tomatoes. Overall, the development of tomato powder represents a major advancement in food processing, offering a sustainable way to reduce waste and ensure the year-round availability of nutritious, tomato-based products.

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