AMBIENT STABILITY FINDINGS FOR FLAVOURED MILK PRODUCT

After spending three weeks in an incubator at 37 ºC - equivalent to roughly three (3) months of ambient storage - plus approximately on week at ambient conditions during transit, these results represent four months of ambient shelf-life.

The evaluation report contains two sets of data:

1. Samples processed at 118 ºC

2. Samples processed at 12 ºC, which was the preferred processing temperature based on initial trials.

Overview of Observed Instability

From the start of the incubation period, all flavoured milk samples demonstrated some degree of sedimentation, which progressively worsened. While sedimentation after 1 week was moderate, the issue intensified significantly by week 3.

A major concern was found in one strawberry flavoured milk sample processed at 121 ºC with EDTA. This sample exhibited near-complete coagulation, with only minimal free liquid remaining. A substantial coagulated mass was expelled upon opening, and the product showed a low pH of 4.83, compared to the > 6 pH recorded for all other samples. Such a drop in pH is strongly associated with severe heat-induced protein destabilisation.

Bottle deformation was also observed, which raise questions about the retort conditions.

Processing and Retort Considerations

The physical changes in the product and bottles suggest possible issues with retort pressure management:

* Is the retort pulling vacuum? Boiling inside the containers and bottle deformation indicate insufficient counter-pressure.

* Required back pressure: At least 1.5 bar must be maintained during processing to prevent boiling and structural damage.

* Retort type: If a rotor retort (agitating retort) is used, controlling pressure and temperature uniformity becomes even more important for flavoured milk stability.

Formulation Guidance for Flavoured Milk Under Retort Conditions

Flavoured milk is highly sensitive to heat due to its protein content. To ensure better stability:

* Ingoing pH must be above 6.65: Lower pH dramatically increases protein coagulation during high-temperature processing.

* Avoid whey-based proteins in retorted dairy beverages; they denature aggressively. Milk Protein Concentrate (MPC) is the preferred alternative for heat-stable flavoured milk.

* Recommended stabiliser: IfaTech CG100, which is successfully used in a well-known new high-protein milk. This stabiliser provides excellent stability and minimizes sedimentation in retorted dairy systems.

Conclusion

Addressing both retort conditions and formulation factors (pH, protein source, and stabiliser selection) will be crucial for improving heat stability and achieving reliable ambient shelf-life.

• Related Articles

• RECIPE GUIDELINES - SOUR ACIDOPHILUS MILK

  Sour Acidophilus milk is a probiotic drink made by fermenting milk with the bacteria Lactobacillus acidophilus. SACCO LYOFAST YAB 450 AB range Available in 1 UC | 5 UC | 10 UC | 50 UC sachets Dosages: 1 UC enough for 100 L of milk 5 UC enough for 500 ...

• DFI DAIRY BLEND RECIPE - WITH VISCO SE 8 - 12

  NEED A DAIRY BLEND RECIPE WITH VISCO? VISCO SE 8 - 12 IS A BLENDED SWEETENED SYRUP CONTAINING A CARRIER, SWEETENERS, FLAVOURING AND PRESERVATIVES. USED TO REPLACE SUCROSE IN DAIRY CONTAINING BEVERAGES, THEREBY ADDING SWEETNESS WITHOUT CALORIES. ...

• DFI DAIRY BLEND - WITHOUT VISCO SE 8 -12

  NEED A DAIRY BLEND RECIPE WITHOUT VISCO? CONTACT DYNAMIKO FOR YOUR INGREDIENT NEEDS SALESREP@DYNAMIKO.CO.ZA / ORDER@DYNAMIKO.CO.ZA / WA 063 669 1805 ATTACHED: DAIRY BLEND RECIPE WITHOUT VISCO SE 8-12

• HOW TO MAKE VEGAN YOGHURT USING VEGAN STARTER CULTURE?

  INGREDIENTS * 4x CUPS OF PLANTBASED MILK (UNSWEETENED AND UNFLAVOURED). * 1 - 2 TABLESPOONS OF VEGAN YOGHURT STARTER CULTURE. * SWEETENER (OPTIONAL) - AGAVE SYRUP / MAPLE SYRUP / SUGAR - TO FEED THE BACTERIA. EQUIPMENT NEEDED * CLEAN GLASS JARS OR ...

• RECIPE GUIDELINES - MANCHEGO (TYPE)

  Manchego is a well-known Spanish sheep's milk cheese from La Mancha Province. It is a relatively small cheese. The rind is yellowish, covered by protrusions made by the form. The interior is usually straw yellow with an irregular eye formation due to ...