Soluble solids content

Figure 4 and 5 show yield points at soluble solids contents of 35 % and 50 %. 

Grape juice was obtained from a 1 1 mixture of two red cultivars, Benfica and Piriquita . After harvest the grapes were washed, sorted out, crushed, treated with SO2. pressed and kept at 7°C for three days. The juice was filtered and stored at -3 to 0 °C using 0.06% potassium sorbate as preservative. The soluble solids content was 22 °Brix, the pH 3.3, calcium, potassium and magnesium contents were 125, 1170 and 240 mg dm, respectively. 

In the recycling system, soluble solid content of all the samples was bigger than in the nonrecycling system (Figure lb). The recycling system presented the higher value for the oil-rich emulsion from the desludger, while the levels of the other emulsions tended to fluctuate. 

Early studies of Concord and other native grape juices (7, 8) found soluble solids content of these juices in the 12°-20° Brix range and found them to be variable with location and season. The chemical composition of New York State grapes and juices was studied in 1938-1939 ( 9). Brix of Concord juice from ripe fruit from different areas within the state ranged... 

As previously indicated, the evaluation of fruit juice will, as a rule, require an expert appraisal of the entire analysis. In practice there will be key parameters to be noted and adhered to during the manufacture of fruit juices and related products. Of these, the soluble solids content and titratable acidity are the major indicators to be taken into account when identifying the status and suitability of a juice product for use in an application. 

The soluble solids content will relate directly to both the sugars and fruit acids, as these are the main contributors. Pectins, glycosidic materials and the salts of metals (sodium, potassium, magnesium, calcium etc.), when present, will also register a small but insignificant influence on the solids figure. 

Lu, R. (2004) Multispectral imaging for predicting firmness and soluble solids content of apple fruit. Postharvest Biol. Technol. 31(2), 147-57. 

Disadvantages of RO come from its inability to reach the high concentration of juices typically obtained by evaporation, because of osmotic-pressure limitation. As a consequence concentrations larger than 25-30° Brix total soluble solid content (TSS) cannot be reached with a single-stage RO [25]. 

The growing conditions, weather, and day length, previously described, combine to form a set of conditions at harvest time that are often quite different from those found in California vineyards. It is sometimes necessary to delay the harvest of certain varieties to the upper limit of the desired soluble solids content to allow the total acidity of the fruit to be reduced to the desired level. This results in a wine with a relatively high total acidity and potentially with a high ethanol content as well. 

Greensill, C.V., Wolfs, P.J., Spiegelman, C.H., and Walsh, K.B., Calibration transfer between PDA-based NIR spectrometers in the NIR assessment of melon soluble solids content, Appl. Spectrosc., 55, 647-653, 2001. 

Sample Preparation. Kiwifruit of the major commercial variety, Hayward, was obtained locally. The fruit was allowed to ripen at room temperature at which point the soluble solids content of the juice was 16-17%. After separation of the the skin, the pulp was gently blended in a Waring blender taking care not to fracture the seeds. The blended pulp was immediately subjected to vacuum steam distillation. 

In strawberry puree, pressurization above 250 MPa generated a poly-phenoloxidase activity loss of 60%, while peroxidase activity decreased in 25% with pressures above 230 MPa. A combination of temperature and pressure reduced the activity of pectin methyl esterase in orange juice by up to 50% (Cano et al., 1997). As shovm by Basak and Ramaswamy (1996), the inactivation of pectin methyl esterase in orange juice depends on pressure level, time of treatment, pH, and soluble solids content. In Satsuma mandarin juice, 300-400 MPa for 10 min was required to partially inactivate the pectin methyl esterase, which was reactivated neither after treatment nor during storage. This demonstrated that the greater the concentration of soluble solids in the medium the lower the inactivation of the enzyme (Ogawa et al., 1990). 

Liquefaction of fruits and vegetables, to obtain products with increased soluble solids content (pectolytic and cellulolytic enzymes combined). 

Soluble Solids. A Zeiss Opton refractometer was used to determine the soluble solid content of the juice at 20°C. The results are reported in degrees Brix at 20°C. 

The sensory quality of kiwifruit was greatly improved, resulting from the softening of the texture, decrease in acidity, and increase in soluble solid content due to the conversion of starch into sugars. In addition to these changes, there were enzymatic reactions which cause formation of more volatiles that improve the aroma of the fruit. 

As the soluble-solids content increased from 6.3% to 11.4%, soluble-solids/total-solids increased from about 81% to 90%, and the insoluble-solids/total-solids decreased from about 19% to 10%. Although a high soluble-solids content can result in an increase in the pounds of tomato paste, or sauce, per ton of tomatoes, this does not always mean a big advantage for processors that produce high-consistency products. Often the recovery is greater from thick-juice cultivars that express the highest insoluble-solids content. 

Table II. Relationship of Reducing Sugar Content to Soluble-Solid Content in High-Solids Tomato Variants...

The average reducing sugar/soluble solids content was 63.5% The average ratio of fructose/glucose was 1.17. Both values compare with those of standard commercial tomato cultivars (8). 

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