Effect of oven and forced convection continuous tumble (FCCT) roasting on the microstructure and dry milling properties of white maize

Expanded porous-starch matrix as an alternative to porous starch granule: Present status, challenges, and future prospects

Exposing the hydrated-soft-starch matrix of intact grain or reconstituted flour dough to a high-temperature-short-time (HTST) leads to rapid vapor generation that facilitates high-pressure build-up in its elastic matrix linked to large deformation and expansion. The expanded starch matrix at high temperatures dries up quickly by flash vaporization of water, which causes loss of its structural flexibility and imparts a porous and rigid structure of the expanded porous starch matrix (EPSM). EPSM, with abundant pores in its construction, offers adsorptive effectiveness, solubility, swelling ability, mechanical strength, and thermal stability. It can be a sustainable and easy-to-construct alternative to porous starch (PS) in food and pharmaceutical applications. This review is a comparative study of PS and EPSM on their preparation methods, structure, and physicochemical properties, finding compatibility and addressing challenges in recommending EPSM as an alternative to PS in adsorbing, dispersing, stabilizing, and delivering active ingredients in a controlled and efficient way.

Variables related to microwave heating-toasting time and water migration assessment with kernel size approaches of specialty maize types

BACKGROUND

Three main maize types with specialty kernels are used to make ready-to-eat maize by traditional toasting, and microwave toasting may be an innovative application. However, little is known of the toasting process of these Andean maize types. Therefore, the present study aimed to explore the behavior of a broad scope of variables in these maize types. The kernels were packed in sealed paper envelopes and subjected to six microwave heating-toasting times from 0 to 390 s. Subsequently, with actual kernel size approaches, water content (WC), water ratio (WR), and water loss (WL) were analyzed.

RESULTS

In addition to WC, WR, and WL, the surface area (S), volume (V), and geometric mean diameter (GMD) behaved like time-related variables with a high correlation depending on the maize types and kernel dimensions. Thus, the WC, WR, and WL third-order polynomial regression curves computed with the spatial (S/V)² and distance (GMD/2)² approaches indicated the water variation at each microwave heating-toasting time with a clear difference among maize types a0, a1, and a2. Regarding their exchange profiles without and with the spatial (S/V)² approach, the maximum rates showed significant differences between maize types and WC and WL. Likewise, the maximum rates displayed significant differences between the spatial (S/V)² and distance (GMD/2)² approaches, revealing a notable lack of consistency with the distance (GMD/2)² approach.

CONCLUSION

The kernel size approaches revealed that water migration rates depended on differences in maize types. Such basic information represents the first insight into more physical-based models of water diffusion during raw microwave maize heating-toasting. © 2022 Society of Chemical Industry.

Effects of Dry Heat Treatment and Milling on Sorghum Chemical Composition, Functional and Molecular Characteristics

This study aimed to highlight the effects of grains dry heat treatment, flour particle size and variety on sorghum flour nutritional, functional, and molecular characteristics. The results obtained showed that dry heat treatment led to fat, fiber and water absorption capacity increase, while the moisture, protein, ash, water retention capacity, solubility index, foaming capacity, and FT-IR absorption bands characteristic to phytic acids decreased with temperature applied raised. Particle size reduction determined lower protein, solubility index, and emulsifying activity and higher fat content, oil absorption capacity, swelling power, and foaming capacity. White sorghum flour fractions presented lower protein content, except when they were treated at 140 °C, lower carbohydrates and fibers and higher fat content compared to those made of red sorghum. Moderate significant correlations (p < 0.05) were observed between some of the functional properties and proximate composition of flours. Thus, both dry heat treatment conditions and particle size exerted significant influences of sorghum flour chemical and functional properties. These results showed the importance of particle size and dry heat treatment on sorghum flours functionality, being helpful for further optimizations and choices for bakery products use.

An overview of conventional and emerging techniques of roasting: Effect on food bioactive signatures

Roasting is a food processingtechnique that employs the principle of heating to cook the product evenly and enhance the digestibility, palatability and sensory aspects of foods with desirable structural modifications of the food matrix. With the burgeoning demand for fortified roasted products along with the concern for food hygiene and the effects of harmful compounds, novel roasting techniques, and equipment to overcome the limitations of conventional operations are indispensable. Roasting techniques employing microwave, infrared hot-air, superheated steam, Revtech roaster, and Forced Convection Continuous Tumble (FCCT) roasting have been figuratively emerging to prominence for effectively roasting different foods without compromising the nutritional quality. The present review critically appraises various conventional and emerging roasting techniques, their advantages and limitations, and their effect on different food matrix components, functional properties, structural attributes, and sensory aspects for a wide range of products. It was seen that thermal processing at high temperatures for increased durations affected both the physicochemical and structural properties of food. Nevertheless, novel techniques caused minimum destructive impacts as compared to the traditional processes. However, further studies applying novel roasting techniques with a wide range of operating conditions on different types of products are crucial to establish the potential of these techniques in obtaining safe, quality foods.

Application of an expert system of X- ray micro computed tomography imaging for identification of Sitophilus oryzae infestation in stored rice grains

BACKGROUND

The plausibility of image texture analysis to assess X-ray images of S. oryzae-infested rice after variable storage days (fresh, 45, 90, 135, 180 and 225 days) was investigated using an X-ray micro computed tomography instrument. Subsequently, image acquisition, pre-processing, and the extraction of the image textural features was done using volume graphics VGL 2.2 software. Morphological features (radius, diameter, volume, compactness, sphericity, defect volume, and voids) were extracted from the x, y, and z views of the rice grain and used as inputs for principal component analysis (PCA).

RESULTS

Clear grouping was observed between the fresh, 45 and 225-day-old S. oryzae-infested rice grains with a classification accuracy of 88.34%. The voids (884 248.53 μm³ ) and defect volume distribution (137 428.04 μm³ ) were found to be the maximum in 225-day-old samples. The similarity or the distance indices values between fresh and 255-day-old S. oryzae-infested rice samples were found to be 35 038.08, which resulted in clear discrimination between different storage days in S. oryzae-infested rice grains.

CONCLUSION

This work contributes to the potential use of image texture analysis to aid in distinguishing S. oryzae-infested rice grains from fresh rice grains. © 2019 Society of Chemical Industry.