Aerated products

Production of aerated products from nonwheat cereals has been a goal for a long time. Utilization of nonwheat cereals such as sorghum would be enhanced if they could produce breads with consumer acceptance close to that of wheat breads. This would also create a niche market for the fraction of the population that is gluten intolerant (see Chapter 14). Success has been limited. 

The sugar, glucose syrup and any invert sugar are boiled to temperature, cooled, and a solution of the gelling agent of choice is added. The mixture is whipped as required and then deposited in starch moulds. 

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In confectionery manufacture aerated products such as frappe, mazetta, or ice cream are based on the use ot foams. Foams are affected by vapor pressure, surface tension, crystallization, denature-tion, and gelation. The production of foams in aerated icings and in whipped cream products is analyzed. 

All aerated products are technically foams. One point of view is that aerated products are a way of making the public pay for air. This is not true in the case of many bakery products such as bread as the product is not sold by volume but by weight. The only food where this claim could be true is ice cream which is sold by volume not weight. Not only does the consumer pay for the air in ice cream as ice cream is subject to standard rate value added tax the consumer pays VAT on the air as well ... 

The two problems in making an aerated product can be simply stated as making the bubbles and stabilising them when they have been made. 

Use only stainless steel tanks minimize vortex formation to prevent aeration. Product attacks glass avoid contact with glass. 

Pectin has been suggested as an ingredient for aerated products where a compatible whipping agent must also be used in conjunction with a high methoxyl pectin. Typically the product will contain 0.5-2.5% of high methoxyl pectin and some gelatine. 

Once a product has been made, the ability to maintain its stability comes into question. Thus, Chapter 8 covers the topic of shelf life and focuses on the well-known phenomenon of bread-staling and the factors causing it. Starch is the cereal component believed to play the principal role in the staling of aerated products. 

Flour + water + air + energy dough (for aerated products)... 

The balance between viscosity and elasticity is close to optimum for wheat gluten protein at the water content used in dough-making. We have seen that the first requirement for a protein in dough to have viscoelastic properties is that its Tg be below the processing (usually ambient) temperature for the water content used. A second requirement for dough in an aerated product is that the molecular weight distribution (MWD) of the protein be optimal. 

Fig. I. Cyclic voltammograms (I-a, Il-a, Ill-a) at a scan rate of 100 mV s" and RDE voltammograms (I-b, Il-b, Ill-b, c, d) at an electrode rotation rate of 1000 rpm, and a scan rate of 10 mV s on a glassy carbon disk electrode with 0.2 M Na2S04 at 25°C. I for 1 mM -complex 3 at pH 10.0. II for 1 mM Ni -complex at pH 7.3 (Tris buffer) curve a and b for Fe -complex 3, curve c for Fe -complex 7 (aeration product of Fe -complex 3), curve d for free ligand 1 no further oxidation wave was seen up to -f 0.5 V vs. SCE.

Chain and flight Transfer/convey/feed/ metre combined process step - heat, cool Laige lump to powder special consideration for aeratable products Few m to 50 m horizontal to vertical up (20 m) Few tonnes/h to few 100 tormes/h... 

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