AKIHIRO NAKAGAWA

Título da Tese: Uso do amido ceroso para redução de sódio e lipídeos em produtos à base de cereais

 Orientador: Prof. Dr. Antonio Roberto Giriboni Monteiro

Data da Defesa: 17/09/2020

RESUMO GERAL

The search for increasingly healthy foods that are low in salt and low in lipids has been increasingly constant in the lives of consumers. The high rate of cardiovascular problems, kidney disease and hypertension that has plagued the world today has increased the study on how to reduce this danger in food without losing the quality and taste of products.

Much of the success of extruded snacks or snacks is through the coverage that is applied, giving flavour, improving appearance, improving texture, and increasing shelf life in some cases. Salt is a significant contributor to the palatability of foods, by increasing salinity and overall flavour, improving the flavour of other aromatic components through interactions through modal, suppressing bitterness. In both cases, whether in the coverage or the salt content of a food product, it can be said that these are the determining elements in consumer acceptance.

Waxy corn starch is a promising raw material with low paste temperature, high viscosity peak and low final viscosity, indicating that it can swell quickly and retrograde less frequently. These attributes are mainly due to the meagre amount of amylose in its composition, thus enabling the formation of a thick and stable gel even in the presence of large amounts of salt, and after drying it will enable the maintenance of the structure until it has contact with water again, in addition to presenting better digestion than the other types of starches. Therefore, it is a raw material very suitable for food production.

AIMS

Produce a cover as a substitute for vegetable oil in the flavouring of extruded snacks, as well as salt agglomerates that can be used in bread, thereby ensuring the heterogeneous distribution of salt in the product and reducing the sodium content.

MATERIALS AND METHODS

REPLACEMENT OF VEGETABLE OIL IN THE COVERAGE OF EXTRUDED SNACKS

The production of the snacks was made by the extrusion process of corn grits, and in the topping waxy corn starch, guar gum, vegetable oil and seasoned with roasted powdered onion and sodium chloride were used. After being extruded, the snacks were placed in an oven at 60 ˚C for 30 minutes to obtain the standardisation of the product's humidity.

To replace vegetable oil in the flavouring of snacks, five treatments were used (T1 to T5). The production of the toppings consisted of hydrating the corn starch in water at room temperature for 1 minute under agitation followed by the elevation of the gelatinisation temperature, always under agitation. Six cover treatments for aromatisation were prepared: TC0 without cover, TC1 15% vegetable oil, T1 4% waxy starch, T2 3% waxy starch and 0.25% guar gum, T3 2% waxy starch and 0.5 % guar gum, T4 1% waxy starch and 0.75% guar gum and T5 1% guar gum.

The humidity was determined according to OAC 2005 at time 0 and 30 days.

The total lipid content was determined using the Bligh & Dyer method (1959) at time 0 and 30 days. 9

 

The radial expansion index was calculated, according to MERCIER et al. (1998). The diameter was measured using a digital calliper.

The instrumental texture analysis to measure the hardness was performed on the TAXT2 Plus texturometer, according to DISCHSEN et al. (2013).

The specific volume was calculated using the displaced mass volume. The apparent density (in g / ml) was calculated by the mass divided by the volume of 1000ml. The retraction index was calculated based on the decrease in the specific initial volume and after coverage. Agglomeration Index analysis was carried out to measure the adherence of each type of cover, with random samples of 100g of the snack being weighed after tempering and drying, and the formation of clusters (clumps) was counted for each type of cover used.

The sensory analysis evaluated taste and texture characteristics in the form of a hedonic scale according to Monteiro and Cestari (2013), and the data were statistically evaluated by ANOVA, followed by the Tukey test at 5% by the Statistica 7.0 (2004) program.

REDUCING SODIUM IN BREAD

The Salt Agglomerate was produced by mixing and heating water, salt and waxy starch, subsequently dehydrated in an oven, obtaining a concentrated plate of 50% salt and 50% waxy starch, where it was broken and standardised in Tyler sieve sizes between 6 – 9 (2,20 mm – 3,36mm), for use in bread. Three bread treatments were produced, varying only the salt in the formulation: C1 (standard) 1.5% refined salt homogenised in the dough, C2 1.05% refined salt (30% less salt than standard) homogenised in the dough, AS 2.1% (30% less salt than standard, with 50% salt weight + 50% starch weight), and should have 600, 420, 420 (g of sodium / 100g of bread) respectively.

The Brabender farinograph was used, according to the AACC method (2011), the alveography test in the three bread treatments.

The analysis of sodium in the salt agglomerate was performed according to AOAC (1990). Bread colour was measured using Chroma Meter CR400 (Konica Minolta, Japan).

The texture analysis was performed by the TAXT Plus texturometer, following the chewing imitation profile, according to Chen and Opara (2013).

The sensory analysis evaluated the perception of salinity in bread in the form of a hedonic scale, according to Monteiro and Cestari (2013), and the data were submitted to ANOVA analysis of variance, followed by the Tukey test at 5% by the Statistica 7.7 program.

RESULTS AND DISCUSSIONS

REPLACEMENT OF VEGETABLE OIL IN THE COVERAGE OF EXTRUDED SNACKS

The moisture content of the tested samples varied between the initial time and after 30 days (t30), with significant differences for all types of treatment, except for TC0 sample (without coverage). The amount of lipids was higher only in the TC1 treatment due to the addition of 10

 vegetable oil in the cover. Coverings with waxy starch and / or guar gum resulted in a decrease in the lipid content of the products when compared to the product without cover (t30). The decrease in the lipid content would be associated with the increase in the moisture content.

For the results of specific volume and shrinkage index, there was no significant difference for all treatments. In apparent density, there was a significant difference when comparing only the sample without coverage with the other samples with coverage. Vegetable oil coverage (TC1) had no influence on the agglomeration index (IA) of snacks. With waxy starch, this parameter increased, and as the amount of guar gum in the coating increased, there was an increase in the number of lumps in snacks.

There were no significant differences in the texture profile in all treatments. At the same time, the sensorial test obtained better acceptance for the sample with waxy starch with 6.76 points, and 5.96 of the traditional sample with vegetable oil, even without differences significant differences between the average scores obtained.

REDUCING SODIUM IN BREAD

The three samples of masses analysed in the farinograph and alveograph showed no significant differences in the analysed parameters.

The amount of sodium was analysed for the salt agglomerate with waxy starch, and the result was confirmed that there was no loss of sodium chloride in the use of the agglomerate in breads. There were no significant differences in the comparison of the three bread samples for moisture, specific volume and colour in their respective masses.

In the texture profile of the bread, there were no significant differences between treatments.

Through the sensory analysis, it was possible to observe that the sample C2, with 30% less salt than the traditional one, there was a significant reduction in the intensity of salinity compared to the other samples. Samples C1 (traditional) and AS (salt agglomerate with 30% less salt) did not show significant differences in the perception of salt intensity, demonstrating that the non-homogeneous distribution was able to maintain the salt perception, even with the salt reduction.

CONCLUSION

We can conclude that the use of waxy starch in the coverage of extruded snacks showed equality with the traditional method, ensuring low amounts of lipids in the product. Moreover, in the agglomeration of salt and subsequent inhomogeneous dissolution in the bread dough, it proved efficient for maintaining salinity, contributing to the reduction of sodium. In both cases, studies have proved to be feasible in the production of increasingly healthy foods for consumption.

Key words: waxy corn starch; reduction lipids;

Artigos Publicados Vinculados a Tese:

 DOI: 10.3303/CET1975048