The effect of vitamin D coated with tomato pulp fiber on the physicochemical and textural properties of tomato paste

Introduction: After potatoes, tomatoes are one of the most important and widely used vegetables in the world. According to statistics, 70 million tons of tomatoes are produced in the world every year. Currently, China is the largest tomato and tomato paste producer and paste exporter in the world. Most of the tomatoes, more than 60% of them, are used in tomato processing factories, which causes the production of large amounts of pulp or waste. Tomatoes are used to produce products such as tomato juice, paste, puree, ketchup and tomato sauce (Schieber, Stintzing, & Carle, 2001). According to the new approach of the food industry in the production of health-oriented products, the use of tomato pomace, which contains valuable nutritional compounds, has attracted the attention of researchers. On the other hand, tomatoes with beneficial effects on health can be introduced as a suitable alternative to chemical preservatives (Tavakli et al., 2018). In recent years, consumer demand for factory-processed products has increased and has caused researchers to pay attention to the processing of fruit and vegetable waste. A whole tomato contains 9-11% skin, 24-26% seeds and 63-67% pulp. Fresh tomatoes have 5-7.5% dry matter, which includes 22% glucose, 25% fructose, 1% sucrose, 8% protein, 7% pectin, 4% hemicellulose, 8% cellulose, 8% mineral substances, 2 The percentage of dicarboxylic amino acids is 4% malic acid, 9% citric acid and 2% other substances (vitamins, polyphenols, pigments, amino acids and volatile compounds) (Toor et al., 1981). Large amounts of by-products of tomato processing (mainly skin and seeds) are produced by industrial tomato processing factories, where the most serious problem is the accumulation, handling and disposal of waste and by-products of processing. The industrial processing of tomatoes is accompanied by the production of tomato pulp waste (seeds, pulp and skin), which constitutes about 1 to 5% (weight/weight) of all tomatoes processed into tomato products. On the other hand, they are available without the cost of additional raw materials and their use can help create value-added products and their commercial valuation. In recent years, the discussion of food enrichment in the production process of various products, such as dairy products, bread and biscuits, etc., has received attention. One of the important ingredients for vitamin D enrichment is that it allows the body to absorb and metabolize calcium and phosphorus and keeps bones healthy. Considering the importance of removing pulp from the recycling process of factories and on the other hand the importance of enriching processed products with some vitamins, it is necessary to carry out research in the field of vitamin D enrichment coated with tomato pulp powder for tomato paste.

Material and methods: In this study, dried tomato pulp and after separating the peel and grain, whole tomato pulp, peel, the grains were pulverized by milling. Then, each of the obtained compounds was combined with water at 50 ° C and homogenized. After 12 hours and a suitable emulsion it was obtained, vitamin D was added to Samples in four control groups (without adding vitamin D and tomato pulp powder) and samples containing vitamin D with complete pulp fiber coverage (in four levels 2.5%, 5%, 10% and 15%) and samples containing vitamin D with shell fiber cover (in four levels) 2.5%, 5%, 10% and 15%) and samples containing vitamin D were produced with grain fiber coating (in four levels of 2.5%, 5%, 10% and 15%) that all four groups of samples each month, up to six months In terms of durability, the tests defined in this project, such as pH, Brix, color, texture, viscosity, and odor and taste test, were measured by three trained evaluators and Howard test. And the statistical methods in this research were factorial design in the form of a completely random design of 3× 4 which was used with three types of fibers in four levels, in six-time intervals.


Result and discussion: According to the variance analysis table (1-3), as can be seen, only the effect of supplement type and the interaction effect of supplement amount and storage time on the pH changes of tomato paste coated with vitamin D are significant (p<0.01) and the rest of the sources Change has no effect. Researches have shown that tomato seed proteins have good emulsifying properties and water absorption and their emulsion has good stability (De Valle et al., 2006). Tomato skin also contains 10.8% protein, 25.6% ash, 30% fiber, 0.012 lycopene and 0.016% vitamin C (based on wet weight). Based on this, the presence of the mentioned compounds along with vitamin D as a coating can be effective on the pH changes of tomato paste as a coating during storage, which can be due to the hydrolysis of hemicellulosic compounds, lignin and pectin present in the pulp (De Valle et al., 2006). The results obtained from the pH tests of tomato paste indicate that the effect of the type of supplement and the amount of the supplement and storage time on the pH changes of tomato paste coated with vitamin D were significant. The results obtained from the investigations of tomato paste Brix indicate that, except for the effect of supplement type and storage time, other parameters have affected the Brix of tomato paste coated with vitamin D and led to its increase. The results obtained from the studies of tomato salt coated with vitamin D indicate that it had an effect on the salt and led to a change in its amount. The results obtained from the studies on the color of tomato paste coated with vitamin D indicate that it has affected the color number of tomato paste and led to a decrease in the color number. The results obtained from the studies on mold and yeast growth of tomato paste coated with vitamin D have shown that it had an effect on the growth of mold and yeast, so that the core powder had the highest growth and the whole powder had the lowest amount of mold and yeast growth. The results obtained from examining the consistency of tomato paste coated with vitamin D show the significance of this factor, that the consistency of the samples has increased. The results obtained from the investigations on the viscosity of the coated tomato paste indicate an increase in viscosity with the increase in the percentage of powders. The results obtained from investigations on the fenrite of coated tomato paste indicate an increase in phenrite with a decrease in the percentage of powders. The results obtained from examining the chewiness of coated tomato paste, increasing the percentage of powders, especially shell powder, increases chewiness. The results obtained from examining the viscosity of coated tomato paste show an increase in viscosity with a decrease in the percentage of powders. The results obtained from examining the adhesion of coated tomato paste indicate an increase in adhesion with an increase in the percentage of powders. The results obtained from the sensory evaluation studies showed that with the increase in the percentage of slag powder, the acceptance of sensory parameters including color, taste, and texture acceptance and overall acceptance decreased. The results showed that the type of powder with different percentages as a constituent of the coating of tomato paste had a significant effect on most of the mentioned characteristics and a significant difference was observed between them. According to the research, it is suggested to add 2.5% tomato pomace powder, which has a higher color, aroma, texture and overall acceptance than other samples, in products such as ketchup and tomato paste, etc.

Conclusion: According to the obtained results, vitamin D coating using the composition obtained from tomato pulp, in addition to increasing the nutritional value, leads to the stability of vitamin D against heat and its preservation against oxygen and its complete and appropriate distribution in food. Becomes. Since the presence of vitamin D along with tomato pulp compounds that contain calcium and phosphorus, leads to increased absorption of calcium and phosphorus. The results obtained from the investigations of tomato paste Brix indicate that, except for the effect of supplement type and storage time, other parameters have affected the Brix of tomato paste coated with vitamin D and led to its increase. The results obtained from the studies of tomato salt coated with vitamin D indicate that it had an effect on the salt and led to a change in its amount. The results showed that the type of powder in different percentages as the ingredient of tomato paste coating had a significant effect on most of the mentioned characteristics and a significant difference was observed between them.