Comparative Analysis of Vitamin, Mineral Content, and Antioxidant Capacity in Cereals and Legumes and Influence of Thermal Process

Cereals, as the world's most consumed food, face challenges related to nutrient quality due to climate change and increased production impacting soil health. In this study, we investigated the vitamin and mineral content, polyphenols, and antioxidant activity in cereals from Western Romania, analyzing whole and hulled wheat, rye, oat, and soybeans before and after heat treatment. Samples from 2022 crops were processed into dough and subjected to 220 °C for 30 min. The results reveal that, despite efforts to optimize nutrient content, cereals, particularly after heat processing, exhibited lower vitamin and mineral levels than the recommended daily intake. The decrease in polyphenols and antioxidant capacity was notable, with rye flour experiencing the largest decline (15%). Mineral analysis showed copper levels in decorticated wheat decreased by 82.5%, while iron in rye decreased by 5.63%. Soy flour consistently displayed the highest calcium, magnesium, and potassium levels, whereas oat flour had the highest zinc and copper levels before and after heat processing. The study highlights the concerningly low vitamins and minerals contents in cereals, as well as in the final products reaching consumers in the Western part of Romania, and contributes to the assessment of measures that are meant to improve the contents of these minerals.

The Influence of Microwave Treatments on Bioactive Compounds and Antioxidant Capacity of Mentha piperita L

Microwave extraction is becoming a popular option in many fields, especially for bioactive compounds from medicinal plants. This paper addresses the application of microwaves in the process of extracting bioactive compounds (phenols, flavonoids, chlorophyll) from peppermint with antioxidant capacity in order to highlight the influence of the microwave field on the quality of the final product in comparison with the control samples. The Mentha piperita L. is a rich source of phenols. The total phenol content after applying the MW treatments significant increased and varied between 25.000 ± 1.992 and 391.687 ± 20.537 mg GAE/100 g dw compared to the untreated sample (8.089 ± 2.745 mg GAE/100 g dw). The same trend was also recorded in the case of the flavonoid and pigment content in peppermint leaves following the application of microwave treatments. The obtained results were investigated using chemometric multivariate analysis. The main purpose of our research was to compare the possibilities of total or partial substitution of conventional extraction technologies with the microwave extraction technology, and also to highlight the existing differences in the amount of total phenols and flavonoids extracted from peppermint plants in different processing conditions. Through microwave processing, a significant increase in polyphenolic compounds is obtained.

A Comparative Study of Metal Content in Selected Polish and Romanian Honey Samples

The aim of the study was to compare the heavy metal contamination and study the mineral content of Polish and Romanian honeys. We used Polish varietal honeys (n=18) produced in the year 2013-2014 in ecologically clean Podkarpackie region, and Romanian honeys (n=36) from Bihor district produced in 2013. The heavy metals concentration as well as mineral composition of honey was assayed by ICP-OES method with prior microwave mineralization. The cadmium and lead level in tested Polish honeys ranged from 0.007 to 0.021mg/kg and 0.02 to 0.098 mg/kg, respectively. Cadmium was not detected in Romanian honeys, and the lead contamination was lower than in Polish honey (0.018-0.05 mg/kg). Mercury was not detected in any tested honey samples. The aluminum content in Polish honeydew honeys was 34.6-times higher than in Romanian honeys. Honey samples from Poland were richest in potassium (2.5-fold for honeydew, lime and acacia, excluding heather), but they included less calcium. Generally, dark honeys include the highest mineral concentration and are more contaminated by heavy metals. However, all tested samples met the legal requirements for heavy metals residues. The geographical origin and soil composition strongly influenced honey chemical composition and the crucial factor for heavy metal transfer seems to be soil pH.