Nuclear magnetic resonance in chemical structures authentication and pyrolysis oil characterization

Nuclear Magnetic Resonance (NMR) involves the study of nuclei immersed in a static magnetic field and exposed to a second oscillating field. Nuclei have two properties; spin properties and charge properties. Pyrolysis oil is created by dry heating biomass in a reactor without oxygen to around 500 degrees Celsius and then cooling it. Pyrolysis oil is a type of tar that includes too much oxygen to be classified as a pure hydrocarbon. One of the most fundamental methods in synthetic chemistry is using NMR to verify chemical structure. In the literature, little attention has been paid to the application of NMR in the authentication of chemical structures. In this study, we present a use case of NMR to characterize pyrolysis oil and authenticate chemical structures. Results show that the elucidation of chemical compositions of bio-oil is essential for the optimization of its processing technology and exploration of its potential application.

Isoflavone Changes in Immature and Mature Soybeans by Thermal Processing

The isoflavone changes occurring in mature soybeans during food processing have been well studied, but less information is available on the changes in immature soybeans during thermal processing. This study aimed to determine the effect of thermal processing by dry- or wet-heating on the changes in the isoflavone profiles of immature and mature soybeans. In the malonylglycoside forms of isoflavone, their deglycosylation was more severe after wet-heating than after dry-heating regardless of the soybean maturity. The malonyl forms of isoflavones in the immature seeds were drastically degraded after a short wet-heating process. In the acetylglycoside forms of isoflavone, dry-heating produced relatively low amounts of the acetyl types in the immature soybeans compared with those in the mature soybeans. These results were explained by the content of acetyldaidzin being relatively less changed after dry-heating immature soybeans but increasing four to five times in the mature soybeans. More of the other types of acetylglycoside were produced by dry-heating soybeans regardless of their maturity. Acetylgenistin in wet-heating was a key molecule because its content was unchanged in the immature soybeans during processing but increased in the mature soybeans. This determined the total acetylglycoside content after wet-heating. In contrast, most of the acetyl forms of isoflavone were produced after 90 to 120 min of dry-heating regardless of the seed maturity. It can be suggested that the pattern of isoflavone conversion was significantly affected by the innate water content of the seeds, with a lower water content in the mature soybeans leading to the greater production of acetyl isoflavones regardless of the processing method even if only applied for a relatively short time. The results suggested that the isoflavone conversion in the immature soybeans mainly follows the wet-heating process and can be promoted in the application of stronger processing.

Valorization of Rice Straw into Cellulose Microfibers for the Reinforcement of Thermoplastic Corn Starch Films

In the present study, agro-food waste derived rice straw (RS) was valorized into cellulose microfibers (CMFs) using a green process of combined ultrasound and heating treatments and were thereafter used to improve the physical properties of thermoplastic starch films (TPS). Mechanical defibrillation of the fibers gave rise to CMFs with cumulative frequencies of length and diameters below 200 and 5–15 µm, respectively. The resultant CMFs were successfully incorporated at, 1, 3, and 5 wt% into TPS by melt mixing and also starch was subjected to dry heating (DH) modification to yield TPS modified by dry heating (TPSDH). The resultant materials were finally shaped into films by thermo-compression and characterized. It was observed that both DH modification and fiber incorporation at 3 and 5 wt% loadings interfered with the starch gelatinization, leading to non-gelatinized starch granules in the biopolymer matrix. Thermo-compressed films prepared with both types of starches and reinforced with 3 wt% CMFs were more rigid (percentage increases of ~215% for TPS and ~207% for the TPSDH), more resistant to break (~100% for TPS and ~60% for TPSDH), but also less extensible (~53% for TPS and ~78% for TPSDH). The incorporation of CMFs into the TPS matrix at the highest contents also promoted a decrease in water vapor (~15%) and oxygen permeabilities (~30%). Finally, all the TPS composite films showed low changes in terms of optical properties and equilibrium moisture, being less soluble in water than the TPSDH films.

Effect of Thermal Processing on Color, Phenolic Compounds, and Antioxidant Activity of Faba Bean (Vicia faba L.) Leaves and Seeds

The leaves and seeds of the faba bean are good sources of L-3,4-dihydroxyphenylalanin (L-dopa), and are usually eaten with thermal cooking methods. However, little information is available on the effect of thermal treatments on their nutritional value. We compared the changes in color, contents of L-dopa, vitamin C (Vc), total phenolics (TP), total flavonoids (TF) and antioxidant activity after dry heating or steaming faba bean leaves and seeds. The young leaves provided higher values of all the estimate factors, regardless of the thermal treatment. Steaming significantly degraded nutritional values of the leaves, but less changed in seeds, whereas dry heat maintained these attributes. The contents of L-dopa, Vc, TP and TF were shown to have strongly positive correlations with antioxidant activity in the leaves, whereas only L-dopa content was positively correlated with antioxidant activity of the seeds. Faba leaves contained relatively high L-dopa which possessed strong antioxidant activity compared to the Vc. As L-dopa is an important contributor to the antioxidant activity of faba leaves and seeds, consuming L-dopa from leaves may provide beneficial effects not only regarding Parkinson’s Disease.

Bovine Dialyzable Leukocyte Extract IMMUNEPOTENT CRP: Evaluation of Biological Activity of the Modified Product

Dialyzable leukocyte extracts are clinically used under different commercial names (IMMUNEPOTENT CRP®, IMMODIN®, Transferon®) to modulate the immune response altered by pathological conditions such as cancer, inflammation, and viral infections. The purpose of this study is to improve the production process of bovine dialyzable leukocyte extract without decreasing its biological activities (antioxidant, anti-inflammatory, and antitumoral). Our product modification consists of adding a dry heating step in the production process. In this study, we evaluated and compared the chemical composition (bromatological analysis), physical structure (infrared spectroscopy, X-ray diffraction, SEM, and zeta potential) and biological function of the dialyzable leukocyte extracts obtained from fresh and dry bovine spleens. Our results showed that the use of a drying step in the production process of the bovine dialyzable leukocyte extract (bDLE) did not affect its antioxidant and anti-inflammatory effects and it improved its antitumor properties. We suggest that this process modification could be applied to other biological products, such as dialyzable leukocyte extracts derived from other sources, in order to improve its functionality and formulation.