Applications of natural ingredients in savoury food products - Natural Food Additives, Ingredients and Flavourings - page 286

It is rare to use just one type of yeast in a savoury food product and in order to
achieve a balanced fl avour we invariably use a combination of yeasts. For example
using a 50:50 blend of light savoury yeast extract and an enhancing yeast extract
gives a good general enhanced savoury fl avour, the component yeasts working
synergistically with one another. For most meaty savoury foods, a blend of the three
common yeasts above in equal proportions can be recommended. This blend can be
modifi ed for example by replacing a fraction of the dark yeast with a more heat
treated yeast to produce a more roasted type fl avour, if desired. Yeast extracts are
used sometimes in conjunction with both hydrolysed vegetable protein and other
sources of umami, for example, soya sauce, tomatoes, mushroom and green tea
(Umami Information Centre, no date) where the fl avour benefi ts from the synergy
between glutamates and 5′ nucleotides can fully be exploited (Kuntz 2007).

13.2.10 Functional ingredients

Starches
Starches, carbohydrates (C 6 H 10 O 5 ) n found naturally in a wide variety of plant
materials, are used in food products as thickeners, texturisers and stabilisers.
Their functionality is due to a number of factors including the size of starch
granule, which depends on the source material and the structure and ratios of the
amylase and amylopectin molecules present in the starch.
Basic native starches are commonly used in a wide range of savoury food
products; maize, potato and wheat are the most common with rice, pea and tapioca
also becoming more available in recent years. These are acceptable for many
applications especially where no or little processing occurs. For most industrial food
processing, however, a degree of tolerance is required to be built into the starch in
order to cope with low pH, high shear, excess heat and frozen storage conditions.
This was achieved historically by chemical modifi cation of the starch by primary
reactions associated with the hydroxyl group of the starch molecule using techniques
such as cross-linking (for example with phosphorus oxychloride), substitution (for
example acetylating) and conversion (for example by oxidation or pyroconversion).
As alternatives to chemically modifi ed starches, starches made with a patented,
proprietary process using standard food processing techniques have been developed
and can be declared simply as 'native starch'. Their functionality is approaching that
of chemically modifi ed starches and they provide the product developer with viable
alternatives. These are available as cold water thickening and hot water thickening
starches from a number of vegetable origins - most notably potato, tapioca, maize,
waxy maize, potato and waxy rice. Starches may be used as thickeners, texturisers and
also as partial replacements for the fat in a product. They may be selected to provide
various degrees of tolerance to low pH, high shear and extremes of temperature.

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Natural colours
Colours have moved away from synthetic to an almost exclusively natural format
in the last few years. Table 13.5 summarises the popular natural food colours
available to the savoury developer.