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Example 3
Hardening of Fermented Liquid
Whey permeate that had been previously fermented and concentrated to form FACW was used to evaluate the impact on hardening time of adjusting pH with NH4(OH) and NaOH. The original pH of the FACW was 5.57 and 60% solids. Two pH levels were evaluated, pH 5.82 and 6.32, and they were set by using either NH4(OH) and NaOH to increase the pH of the FACW (4 treatments). For each of the four FACW treatments, 320 g was placed in a mixing bowl and mixing was initiated. Then 80 g of calcium chloride was slowly added over a total mixing time of 20 minutes. Subsequently, the mixture was poured into foil-lined trays and held at ambient temperature (74° F.). The mixtures were evaluated every 10 minutes for hardness. FACW which had pH adjusted to 5.82 and 6.32 reached a hard state by 90 and 60 minutes, respectively. In contrast, FACW that had pH adjusted with NaOH did not reach hardness. Results are presented in
Example 1
Fermentation/Concentration
In some embodiments, whey permeate, concentrated permeate, and/or ultrafiltration permeate is pasteurized and then fermented with Lactic acid bacteria for 20 to 30 hours at 10-130° F. with injection of NH4(OH) to maintain pH at 5.5 to 5.6 during fermentation. The resulting fermented liquid is concentrated by mechanical vapor recompression (MVR) to achieve a solids content of about 58%-64%. The concentrated fermented liquid is then sent to a pH balance tank where it is injected with NH4(OH) to achieve a pH of about 6.5 to 6.7.
Crystallization
The concentrated fermented liquid is then sent to a plate heat exchanger (PHE) to bring the temperature of the liquid to about 130° F. The concentrated fermented liquid is then sent to a crystallization tank where the concentrated fermented liquid is agitated and allowed to cool to about 110° F. to 115° F., during which crystal formation occurs. In some embodiments, once the temperature of the concentrated fermented liquid reaches about 90° F. to 115° F. the concentrated fermented liquid is sent to a decanter centrifuge to separate the solid crystals from the liquid. Across 12 fermentation batches from production, the average yield of solid crystals was 1,744 lb.
Across multiple processing trials the following crystal yields were achieved:
Example 2
Fermentation/Concentration
In some embodiments, whey permeate, concentrated permeate, and/or ultrafiltration permeate is pasteurized and then fermented with Lactic acid bacteria for 20 to 30 hours at 100-120° F. with injection of NH4(OH) to maintain pH at 5.5 to 5.6. The resulting fermented liquid is concentrated by mechanical vapor recompression (MVR) to achieve a solids content of about 61%-64%.
Crystallization
The concentrated fermented liquid is then sent directly to a crystallizer tank with continuous agitation. In this example, the liquid is not sent to pH balance tank or chiller plate heat exchanger. To achieve higher crystal yield, a 3000 (w/w) CaOH slurry is added to the concentrated fermented liquid in the crystallization tank to achieve a calcium concentration of 0.9-2.0% (w/w) in the combined mixture. The CaOH slurry is added to the concentrated fermented liquid in the crystallizer tank slowly to allow thorough mixing. The mixture is then allowed to stand in the crystallization tank for 6 to 18 hours, during which time the temperature is allowed to cool to about 90 to 115° F. and crystals are formed. Once the temperature of the concentrated fermented liquid reaches about 90 to 115° F. the concentrated fermented liquid is sent to a decanter to separate the solid crystals from the liquid.
Across multiple processing trials the following crystal yields were achieved with a calcium concentration of 3.33% (non-seeded data from Example 1 is included for comparison):
Example 5
Whey permeate that had been previously fermented and concentrated to form FACW was used to evaluate the impact on hardening time when adjusting to different pH with NH4(OH). The original pH of the FACW was 5.57 and solids of 60%. Two additional pH levels 5.82 and 6.32 were set by using NH4(OH) and evaluated. For each of the three pH levels, 320 g of FACW was placed in a mixing bowl and mixing was initiated. Then 80 g of calcium chloride was slowly added over a total mixing time of 20 minutes. Subsequently, the mixture was poured into foil-lined trays and held at cooled temperature (38° F.). The mixtures were evaluated every 10 minutes for hardness. FACW which had pH adjusted to 5.57, 5.82 and 6.32 reached a hard state by 60, 40 and 20 minutes, respectively. Results are presented in
Example 4
Whey permeate that had been previously fermented and concentrated to form FACW was used to evaluate the impact of temperature on hardening time. The FACW solids was 60%. The effect of temperature was evaluated by holding samples at either ambient temperature (i.e. 74° F.) or at a cooled temperature (i.e. 38° F.) during the period where samples were left to harden. Firstly, 320 g was placed in a mixing bowl and mixing was initiated. Then 80 g of calcium chloride was slowly added over a total mixing time of 20 minutes. Subsequently, the mixture was poured into foil-lined trays and held at either at ambient or cooled temperature. The mixtures were evaluated every 10 minutes for hardness. FACW that was held at the cooled temperature reached a hard state at 40 minutes. In contrast, FACW held at the ambient temperature reached a hard state at 70 minutes. Results are presented in