Bake mix performance testing

The Perten RVA is an instrument that measures quality and performance in flour-based mixes for baking and extrusion. It detects abnormal incoming ingredients as they enter the plant, and flags poor-performing mixes before they go any further.

Demonstrating RVA Capabilities

Background:

A research team from the Northern Crops Institute in Fargo, ND designed an experiment that would show whether the RVA yielded more discriminative results than test bake results - in cake and cookie mixes with deliberately altered levels of primary and functional ingredients, compared to “normal” controls. The goal was to answer several questions:

  • How well does the RVA detect over and under-doses of bake mix components?
  • How well does test baking detect over and under-doses of bake mix components?
  • Is the RVA, statistically, a better detector of these problems in mixing than test baking?

Materials & Methods:

Commercial cake & pastry flour and ingredients were purchased to serve as components for creating cake and cookie bake mixes. The ingredients included mono and diglycerides, egg powders, vanilla flavor, shortening, non-fat dry milk, granulated sugar, sodium bicarbonate, soybean oil and salt. For cakes, red cocoa and sodium aluminum phosphate were provided.  For cookies, modified food starch and emulsifier were provided. Each product sample set contained a control formulation, a double-dosing, and an ingredient omission. This resulted in a total of 15 treatments of each product.  Treatments included variations of baking soda, salt, powdered egg, NFDM, sugar and flour for both cookies and cakes in addition to cocoa and vanilla for cake and cookies, respectively.

Test Baking

Dry mixes were prepared using a standardized mixing protocol. Each mix was then baked under standardized conditions. The cakes and cookies were allowed to cool and were analyzed the next day. Cake attributes were measured by randomly selecting one cake from each treatment and cutting it in half to measure diameter and height. The measured values were used to obtain total cake volume and shrinkage value. Percent weight loss due to moisture loss was calculated by weighing the products before and after baking.  Specific gravity was obtained by dividing the weight of 100 ml batter by the weight of 100 ml water.  Specific volume was calculated as the inverse of specific gravity. Cake volume was measured using a laser-based volumeter and texture with a texture analyzer. For cookies, the average diameter and height of six cookies was calculated and the moisture loss was calculated by weight loss as described above.

RVA Analysis

A Rapid Visco Analyser (RVA) was used to measure the pasting properties of cake and cookie mixes using a test bake mix test profile. Relative to the standard pasting profile for flour, this profile provides a slower rate of heating during the last stage of temperature increase. This slower heating ramp is intended to draw out small differences in pasting performance of similar but discrepant cake mixes. A consistent dry mix to water ratio of 8 g to 25 g was used without taking moisture content into consideration. Batches of dry mix with individual alterations were prepared in duplicate, and each batch was analyzed in duplicate. Functionality of each ingredient was further studied by testing single ingredients in combination with flour.

Results & conclusions

The complete results are available in an article in Cereal Foods World. The conclusions were that functional ingredients, including flour, egg, baking soda, and sugar, significantly affected RVA pasting curves and baking parameters, while NFDM, cocoa or vanilla did not show significant effects.  Except for eggs, the baking test did not differentiate the baked cakes’ and cookies’ controls from the various altered formulations. The RVA clearly differentiated cake and cookie premixes with high and low levels of key ingredients, giving repeatable results in a timely manner (21 minutes), The results of this study demonstrate the RVA is a more effective, sensitive, and rapid method than test baking for evaluating bake mix quality and performance.

Plot example of effect of sugar on RVA curve

RVA-MP for Bake Mixes

Uses & Benefits of the RVA for mix performance testing:

Screen  every batch for performance

Pancake mix analysis with the RVA


Compositional analysis (moisture, fat, protein, ash, etc.) is important, but it doesn’t describe whether an ingredient or a mix is actually any good. The ultimate measure of quality is to measure the real performance of an ingredient or mix - putting it through its paces in a tightly-monitored cooking process.

  • The RVA measures mix performance under reproducible cycles of heating cooling, and mixing.
  • This allows for direct comparison of supposedly identical mixes or ingredients.
  • Detecting abnormal ingredients and mixes  reduces downstream waste.
  • Because the RVA measures cooking performance, it reduces the need for costly, subjective test bakes.

The important thing is to measure the cooking performance of the mix, accurately detecting problems in quality. The RVA does that.

Why reduce or eliminate test bakes?Bake mix muffin analysis with the RVA

Test baking:

  • Takes lots of time and labor
  • Subjective, variable, vulnerbale to operator variances
  • Means finished product builds up waiting for release
  • Does not always catch bad product

The RVA protects your brand better than test baking. It’s faster, easier, more discriminative, more traceable, and cheaper than test baking.

  • Accurate – Identify abnormal ingredients before they ever enter your production.
  • Fast –  Screen every batch of bake mix before packaging or baking.
  • Easy –  Operator friendly software, disposable sample modules, minimal operator input. Robust  – Built to withstand industrial environments
  • Profitable - Reduce costly bake tests, bad ingredients, and downstream waste.
  • Perfect Mixes – Ensure all ingredients perform well and are present in the right proportion.

Read more about the RVA here.