The effect of cultivar, maturity stage and storage environment on quality of tomatoes

Partitioning of invertase from tomato in poly(ethylene glycol)/sodium sulfate aqueous two-phase systems

Three-phase partitioning as a rapid and efficient method for purification of invertase from tomato

Microbial invertases: A review on kinetics, thermodynamics, physiochemical properties

Mechanical properties of the horticultural products play an important role in improving the products quality and storage life after harvesting and also reducing product waste. Recently, using organic fertilizers has increasing trend for producing high-quality products as well as improvement of soil quality. Two of the best options to produce organic material and sustainability of agricultural production are vermicompost and sheep manure. The present study relied on determination of mechanical properties through pressure and shear tests. Vermicompost and sheep manure were used separately to fertilize the soil. After planting tomato seeds and harvesting, tomato fruits were analyzed by a universal test machine. The results showed that vermicompost was a better fertilizer than sheep manure due to its more appropriate carbon to nitrogen ratio (C/N), acidity, and salinity. Also, in the pressure test, the maximum force required for bruise of tomato produced with vermicompost (41.5N) was more than that of control sample (no fertilizer) and sheep manure. In the shearing test, the maximum force required for shearing tomato produced with vermicompost (58.60 N) was lower than that of control sample (no fertilizer) and sheep manure. The findings of this study can be used to reduce the amount of waste at different stages of tomato production and supply including the design and optimization of processing and transportation equipment.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/fsn3.877

Influence of vermicompost and sheep manure on mechanical properties of tomato fruit

Enzyme activities in tomato juice of five different varieties viz. Ratan, Marglove, BARI-1, BARI-5 and BARI-6, in relation to sugar accumulation were investigated at different maturity stages. The highest amount of invertase and β-galactosidase was found in Marglove and the lowest in BARI- 6 at all maturity stages. Total soluble sugar and sucrose contents were highest in BARI-1 and lowest in BARI-6. The activity of amylase was maximum in Ratan and minimum in Marglove. Protease activity was highest in Ratan and lowest in BARI-6. BARI-1 contained the highest cellulase activity and the lowest in BARI-5. The amount of total soluble sugar and sucrose increased moderately from premature to ripe stage. The activities of amylase and cellulase increased up to the mature stage and then decreased drastically in the ripe stage. The activities of invertase and protease increased sharply from the premature to the ripe stage while the β-galactosidase activity decreased remarkably. No detectable amount of reducing sugar was present in the premature stage in all cultivars of tomato but increased thereafter upto the ripe stage. The highest reducing sugar was present in BARI-5 in all of the maturity stages.

Enzyme activities in relation to sugar accumulation in tomato

The enzyme invertase (β-D-fructofuranoside fructohydrolase; E.C. 3.2.1.26) was isolated and partially purifi ed from healthy tomato juice. The purifi cation involved buffer extraction, DEAE- cellulose and Sephadex G-75 chromatography. The purity of the enzyme preparation was determined by SDS-PAGE. The enzyme was purifi ed 29.9 fold with 23.19% yield, giving a fi nal specifi c activity 87.62 U/mg. The molecular weights of the purifi ed enzymes measured by gel fi ltration chromatogra- phy and SDS-PAGE were found to be 54 kDa and 49 kDa, respectively. The purifi ed invertase was a glycoprotein with 17.5% sugar. The optimum pH of the purifi ed enzyme was 5.5 and the activity was stable at pH 3.5-7.5. The enzyme showed maximum activity at 35oC and was found to be stable at the temperature ranged from 10oC to 35oC. The K m value of this enzyme for sucrose was 4.5 mM at pH 5. Tris, glucose and fructose reduced invertase activities poorly while urea, EDTA, acetic acid, Zn 2+ and Cd 2 + decreased moderately. Ag+ and Al 3 + produced a slight inhibitory effect on invertase activity. Ca 2+ had almost no effect on tomato invertase activity. Mn 2+ , Mg 2+ , K+, Na+ and Ba 2+ increased invertase activity slightly, while Cu 2+ accelerate invertase action moderately. Hg 2+ almost completely ceased the

M. Habibur Rahman

Papers

Enzyme activities in relation to sugar accumulation in tomato

Extraction, partial purification and characterization of tomato invertase