Biochemical properties of six varieties of tomato from Brong Ahafo region of Ghana as influenced by the ripening condition and drying

Abstract

The study was conducted to assess the influence of the ripening condition and drying on the biochemical properties of six varieties of tomatoes (Lycopersicum esculentum). The six varieties (Tatiana, Techiman, Tropimech, Pectofade, Rodade and Pawa) were obtained from different tomato growing centres of the Brong Ahafo region of Ghana. Fresh fruits were harvested at mature green, half ripe and full ripe conditions using the USDA colour chart for ripening. Fruit samples were sliced and dried in a solar dryer for six days. Biochemical analysis was carried out on samples of both the dried slices and fresh fruits to estimate the vitamin C content, total soluble solids, pH, titratable acidity, moisture and dry matter contents of the six varieties. The results showed significant differences (p<0.05) among the biochemical properties of the six varieties.The vitamin C content of the varieties ranged between 10.37 and 21.25mg/100g. High moisture content, ranging between 83.24 -96.67 percent was recorded for the six varieties. The means of the vitamin C, moisture content, pH and dry matter content were significantly different among the six varieties studied. Although the total soluble solids ranged from 2.70 to 4.17%, there was no significant difference among the varieties. The ripening condition of the fruits did not have any significant effect on the biochemical properties studied. The study revealed that drying significantly affected the biochemical properties of tomato, except the titratable acidity and the total soluble solids. Drying significantly (p<0.05) reduced the vitamin C, total soluble solids, and the moisture contents of the six varieties. As expected, the pH and the dry matter content increased significantly (p<0.05) after drying. Significant correlations were observed among the biochemical properties studied. It can be concluded that some of the six varieties studied have appreciable levels of vitamin C, dry matter, total soluble solids and titratable acidity which could be improved for industrial purposes. In respect to the biochemical properties studied, Pawa appears to be the best variety for industrial processing because of the high Total Soluble Solid (TSS) as well as lower pH and TA values, which are important quality attributes of tomato meant for processing. Tropimech and Techimanare are recommended for fresh market because of the high vitamin C and moisture contents. Although drying could be used to preserve the nutritive value of tomatoes meant for food, it is not recommended for fruits meant for processing because it reduces the TSS content.

Antimycotic Potential of Alum on Postharvest Deterioration of Tomato

“…Although, prior studies on ripe/deteriorating tomatoes indicate that the pH range from 3.9-4.5 and such increase could be influenced by ripeness level, ratio of sugars, length of storage, total acids [69][70][71]39,72,73] and in part by fungal colonization as depicted in this study. Decrease in TTA values may be attributed to changes in citric acid alone or both citric and malic acid or to the ratio of malic and citric acids which may be linked to the conversion of malic to citric acid due to advancement in maturity and/or storage [39,9,[73][74][75][76]] characteristic of deteriorating over ripe tomatoes.…”

Growth, Yield and Biochemical Characteristics of Tomato (Solanum lycopersicum L.) Genotypes under Seasonal Heat Stress

“…Low pH is associated with high fruit quality [15]. Tomato is considered acidic if it has a pH of less than 4.5 [16] and it is a desirable trait because it halts proliferation of microorganisms in processed product [17]. All the tested genotypes in our study had pH lower than 4.5 and most of the South Asian consumer prefer sour taste in fresh tomato.…”

Postharvest Reduction of Salmonella enterica on Tomatoes Using a Pelargonic Acid Emulsion

“…These actions lead to cell leakage and desiccation, similar to the effect seen on PEL-exposed bacteria [ 22 , 24 , 54 ]. Due to chemical and structural differences, it is possible that other tomato cultivars or stages of maturity may be more tolerant to the phytotoxic activity of PEL [ 55 , 56 , 57 ]. Incorporation into polysaccharide films, such as pullulan and chitosan, has shown promise for other antimicrobials used on fresh produce and may be a useful delivery mechanism for PEL-based sanitizers [ 58 ].…”