RESUMO
Environmental and food security challenges due to a growing world population may be overcome by using alternative protein sources for the human diet. By-products from edible oil processing industries are potential sources due to their high protein content. Pumpkin seed meals were evaluated regarding proximate composition, in vitro protein digestibility (IVPD), amino acid profile and score, and antinutritional factors. Conventional thermal processing, microwave, and ultrasound treatments impact on samples' nutritional quality were assessed using a central composite experimental design. Raw pumpkin seed meal presented up to 45% protein content and 86% IVPD. Processing increased IVPD up to 96%, with optimized conditions of 87.8 °C, pH8.0, and 37 min, for all processes. Lysine was the only limiting amino acid for raw and processed samples. Phytic acid decreased by 31%, while trypsin inhibitory activity was reduced by 84%. Pumpkin seed by-product is a promising high-quality plant protein source for food formulations.
Assuntos
Cucurbita , Humanos , Cucurbita/química , Manipulação de Alimentos , Aminoácidos/análise , Proteínas de Plantas/análise , Refeições , Sementes/químicaRESUMO
Protein from plant sources is claimed alternatives to animal sources in the human diet. Suitable protein sources need high protein digestibility and amino acid bioavailability. In terms of protein functionality and food applications, they also need high-quality attributes, such as solubility, gelling, water- and oil-holding capacities, emulsifying, and foaming. Thermal processing can improve the nutritional quality of plants with some disadvantages, like reducing the assimilation of micronutrients (vitamins and minerals). Emerging technologies-such as ultrasound, high-pressure, ohmic heating, microwave, pulsed electric field, cold plasma, and enzymatic processes-can overcome those disadvantages. Recent studies demonstrate their enormous potential to improve protein techno-functional properties, protein quality, and decrease protein allergenicity. However, the literature lacks a broader evaluation, including protein digestibility, industrial-scale optimization, and exploring applications to these alternative protein sources.
RESUMO
Proteins are essential macronutrients for the human diet. They are the primary source of nitrogen and are fundamental for body structure and functions. The plant protein quality (PPQ) refers to the bioavailability, digestibility, and amino acid composition. The digestibility specifies the protein quantity absorbed by an organism relative to the consumed amount and depends on the protein structure, previous processing, and the presence of compounds limiting the digestion. The latter are so-called antinutritional factors (ANF), exemplified by phytates, tannins, trypsin inhibitors, and lectins. Animal proteins are known to have better digestibility than plant proteins due to the presence of ANF in plants. Thus, the inactivation of ANF throughout food processing may increase the PPQ. New food processing, aiming to increase the digestibility of plant proteins, and new sources of proteins are being studied for the animal protein substitution. Here, it is presented the impact of processing on the protein digestibility and reduction of ANF. Several techniques, such as cooking, autoclaving, germination, microwave, irradiation, spray- and freeze-drying, fermentation, and extrusion enhanced the PPQ. The emerging non-thermal technologies impact on protein functionalities but require studies on the protein digestibility. How to accurately determine and how to improve the protein digestibility of a plant source remains a scientific and technological challenge that may be addressed by novel or combining existing processing techniques, as well as by exploring protein-enriched by-products of the food industry.
Assuntos
Digestão , Proteínas de Plantas , Aminoácidos , Animais , Proteínas Alimentares , Manipulação de Alimentos , Humanos , Inibidores da TripsinaRESUMO
Benzyl propionate is an aromatic ester that possesses a fruity odor and is usually found in nature in the composition of some fruits such as plums and melons. This work aimed for the benzyl propionate synthesis by esterification using a new immobilized enzyme preparation with low-cost material from Candida antarctica (NS 88011) and three commercial immobilized lipases (Novozym 435, Lipozyme TL-IM and Lipozyme RM-IM). Novozym 435 had the best performance even when the solvent tert-butanol was absent of the reaction medium. Results from a 22 factorial design showed that an increase in the enzyme amount led to a higher conversion, even when the temperature was kept at the low value. Currently, no research had synthesized successfully benzyl propionate via esterification mediated by lipases; and we reached an ester conversion of ~ 44% after 24 h indicating that it is a promising route for benzyl propionate biotechnological production.