Laura B. Iturriaga

Microencapsulation of betalains obtained from cactus fruit (Opuntia ficus-indica) by spray drying using cactus cladode mucilage and maltodextrin as encapsulating agents

The microencapsulation of betalains from cactus fruit by spray drying was evaluated as a stabilization strategy for these pigments. The betalains used as active agent were extracted from purple fruits of Opuntia ficus-indica (BE) and encapsulated with maltodextrin and cladode mucilage MD-CM and only with MD. The microcapsulates were characterized by scanning electron microscopy (SEM), thermal analysis (TGA-DSC), tristimulus colorimetry, as well as, their humidity, water activity and dietary fiber content were also determined. The active agent content was measured by UV-Vis spectrophotometry and its composition confirmed by HPLC-ESIMS. A pigment storage stability test was performed at 18 °C and different relative humidities. The addition of CM in the formulation increased the encapsulation efficiency, diminished the moisture content, and allowed to obtain more uniform size and spherical particles, with high dietary fiber content. These microencapsulates are promising functional additive to be used as natural colorant in the food industry.

Encapsulating betalains from Opuntia ficus-indica fruits by ionic gelation: Pigment chemical stability during storage of beads.

Betalain encapsulation was performed by ionic gelation as a stabilization strategy for these natural pigments. Betalains were extracted from purple cactus fruits and encapsulated in calcium-alginate and in combination of calcium alginate and bovine serum albumin. Beads were characterised by scanning electron microscopy and thermal analysis using differential scanning calorimetry and thermogravimetry. Moisture sorption isotherms were determined. Bead morphology was affected by matrix composition. Pigments storage stability was evaluated at different equilibrium relative humidity and temperatures. Pigment composition of beads was determined by HPLC-MS-MS and degradation products were also analysed after storage; betalamic acid being the major one. Both types of matrices protected the encapsulated pigments, being their storage stability better at low relative humidity than that of the non-encapsulated control material. Antiradical activities of beads were proportional to remaining betalain contents. At high relative humidity, there was no protection and low storage stability was observed in the samples.

Lactic Acid Fermentation Improved Textural Behaviour, Phenolic Compounds and Antioxidant Activity of Chia (Salvia hispanica L.) Dough

In this work, autochthonous lactic acid bacteria (LAB) were isolated from chia (Salvia hispanica L.) dough and selected on the basis of the kinetics of acidification and proteolytic activity. Strain no. C8, identified as Lactobacillus plantarum C8, was selected and used as starter to obtain chia sourdough. Lactic acid fermentation increased the organic acid mass fractions (lactic, acetic and phenyl lactic acids to 12.3 g, 1.0 g and 23.8 µg per kg of dough respectively), and antioxidant activities, which increased by approx. 33-40% compared to unfermented chia flour dough. In addition, total phenolic content increased 25% and its composition was strongly modified after 24 h of fermentation by L. plantarum C8. Chlorogenic acid was only found in the fermented dough (2.5 mg/g), while ferulic acid was detected from the beginning of fermentation, being 32% higher in chia sourdough (5.6 mg/g). The use of fermented chia sourdough improved the overall characteristics of white bread, including physical (e.g. reduced hardness and chewiness of the crumb) and antioxidant properties (25% on average), compared to the white bread. These results indicate that the use of chia sourdough could be a promising alternative to improve the technological and antioxidant properties of wheat bread. In addition, this work has shown, for the first time, that lactic acid bacterium is able to ferment chia dough, improving its overall characteristics.

Amaranth: An Andean Crop with History, Its Feeding Reassessment in America

This chapter refers to the history of amaranth crop in America and its nutritional revaluation of recent decades. The composition of macro- and micronutrients in grains and leaves, the morphological structure of its grain, and levels of undesirable substances (anti-nutritional and toxic compounds) are described. The latest studies of the main functional properties (emulsifying, hydration, gelling, and foaming) of amaranth carbohydrates and protein are included. These properties affect directly and indirectly the processing and/or storage of food, its quality, and its acceptability and impact on sensory character, especially the texture. Finally, its potential industrial application and the challenges to increase consumption of amaranth are presented.

Functional Components and Medicinal Properties of Cactus Products

The chapter refers to the cactus plants, specially the Opuntia genus, that grow up in arid and semiarid environments under hard hydric stress conditions. The functional phytochemicals of the plant parts, such as fruits, cladodes, flowers, and seeds, and their uses in food preparations are described. A revision of the bioactive constituents, like mucilage, fibers, pigments, and antioxidants, was done, indicating that the cactus plants may be efficiently used as a source of these compounds. This plant is consumed both as fresh foods, e.g., fruits, fresh cladodes named “nopalitos,” and their juices, and processed products such as nopal flour, keeping its functional properties. A review of the latest reports about the medicinal properties of the cactus products is included, showing the benefits to prevent different diseases. This chapter describes cacti as multifunctional plants that offer the possibility of taking advantages from the whole plant, which impacts positively on regional economies of arid and semiarid lands where population deals with subsistence economies.