Leandro de Morais Cardoso

Sorghum (Sorghum bicolor L.): Nutrients, bioactive compounds, and potential impact on human health.

ABSTRACT Sorghum is the fifth most produced cereal in the world and is a source of nutrients and bioactive compounds for the human diet. We summarize the recent findings concerning the nutrients and bioactive compounds of sorghum and its potential impact on human health, analyzing the limitations and positive points of the studies and proposing directions for future research. Sorghum is basically composed of starch, which is more slowly digested than that of other cereals, has low digestibility proteins and unsaturated lipids, and is a source of some minerals and vitamins. Furthermore, most sorghum varieties are rich in phenolic compounds, especially 3-deoxyanthocyanidins and tannins. The results obtained in vitro and in animals have shown that phenolics compounds and fat soluble compounds (polycosanols) isolated from sorghum benefit the gut microbiota and parameters related to obesity, oxidative stress, inflammation, diabetes, dyslipidemia, cancer, and hypertension. The effects of whole sorghum and its fractions on human health need to be evaluated. In conclusion, sorghum is a source of nutrients and bioactive compounds, especially 3-deoxyanthocyanidins, tannins, and polycosanols, which beneficially modulate, in vitro and in animals, parameters related to noncommunicable diseases. Studies should be conducted to evaluate the effects of different processing on protein and starch digestibility of sorghum as well as on the profile and bioavailability of its bioactive compounds, especially 3-deoxyanthocyanidins and tannins. Furthermore, the benefits resulting from the interaction of bioactive compounds in sorghum and human microbiota should be studied.

Effects of processing with dry heat and wet heat on the antioxidant profile of sorghum

The effects of domestic processing with dry heat (F2-oven/milling; F3-milling/oven; F4-microwave oven/milling; F5-milling/microwave oven; F6-popped grains/milling) and wet heat (F7-cooking in water/drying/milling) on the antioxidant profile of sorghum flours (F1-raw flour) were evaluated. 3-Deoxyanthocyanidins and total phenolic compounds were stable to dry heat (retention between 96.1% and 106.3%) and reduced with wet heat. All processing with dry heat increased the vitamin E content (2,201.9-3,112.1 μg/100 g) and its retention, and reduced the carotenoids (4.78-17.27 μg/100 g). The antioxidant activity in processed flours with dry heat remained constant (F3 and F6) or increased (F2, F4 and F5) and decreased after processing with wet heat. Overall, the grains milled before processing in oven and in microwave oven retained more vitamin E and less carotenoids than those milled after these processing. In conclusion, dry heat did not affect the phenolic compounds and 3-deoxyanthocyanidins of sorghum, but increased the vitamin E and antioxidant activity, and reduced the carotenoids. The wet heat processing reduced all antioxidant compounds except carotenoids, which increased.

Tocochromanols and carotenoids in sorghum (Sorghum bicolor L.): diversity and stability to the heat treatment.

The content and stability (retention) to dry heat in a conventional oven (DHCO) and extrusion of tocochromanols and carotenoids in sorghum genotypes were evaluated. One hundred sorghum genotypes showed high variability in tocochromanol content (280.7-2962.4 μg/100g in wet basis) and 23% of the genotypes were classified as source of vitamin E. The total carotenoid varied from 2.12 to 85.46 μg/100g in one hundred sorghum genotypes. According to the genetic variability for carotenoids and tocochromanols, the 100 genotypes were grouped into 7 groups. The retention of the total tocochromanols and α-tocopherol equivalent decreased after extrusion (69.1-84.8% and 52.4-85.0%, respectively) but increased after DHCO (106.8-114.7% and 109.9-115.8%, respectively). Sorghum carotenoids were sensitive to extrusion (30.7-37.1%) and DHCO (58.6-79.2%). In conclusion, the tocochromanols profile in sorghum varied widely and the genotypes presented high genetic variability for carotenoids and tocochromanols. Sorghum was a source of tocochromanols, which increased after DHCO and decreased after extrusion. The carotenoid content in sorghum decreased after DHCO and extrusion.

Effect of the storage time and temperature on phenolic compounds of sorghum grain and flour.

This study evaluated the effect of storage temperature (4, 25 and 40°C) and time on the color and contents of 3-deoxyanthocyanins, total anthocyanins, total phenols and tannins of sorghum stored for 180days. Two genotypes SC319 (grain and flour) and TX430 (bran and flour) were analyzed. The SC319 flour showed luteolinidin and apigeninidin contents higher than the grain and the TX430 bran had the levels of all compounds higher than the flour. The storage temperature did not affect most of the analyzed variables. The content of most of the compounds reduced during the first 60days when they became stable. At day 180, the retention of the compounds in the genotypes SC319 and TX430 ranged from 56.1-77.9% and 67.3-80.1% (3-deoxyanthocyanins), 88.4-93.8% and 84.6-96.8% (total anthocyanins) and 86.7-86.8 and 89.4-100% (phenols) respectively. The retention of tannins ranged from 56.6 to 85.3%. The color of samples remained stable for 120days.

Comparing sorghum and wheat whole grain breakfast cereals: Sensorial acceptance and bioactive compound content

The sensory acceptance and the content of bioactive compounds of whole-sorghum and whole-wheat breakfast cereals were compared. Sensory acceptance was assessed using the Food Action RatingScale. 3-Deoxyanthocyanidins, flavones and flavanones were determined by high-performance liquid chromatography (HPLC) with diode array detection, and vitamin E by HPLC with fluorescence detection. Total phenolics and antioxidant activity were determined by spectrophotometry. The sorghum breakfast cereal had better sensory acceptance (70.6%) than wheat breakfast cereal (41.18%). Sorghum had higher 3-deoxyanthocyanidin content (100% higher), total phenolic compounds (98.2% higher) and antioxidant activity (87.9% higher) than wheat breakfast cereal. Flavones and flavanones were not detected in both breakfast cereals. Total vitamin E content was 78.6% higher in wheat than in sorghum breakfast cereal. Thus, consumption of whole sorghum breakfast cereal should be encouraged, since it had good sensory acceptance and is a source of bioactive compounds that can promote benefits to human health.

Nutritional and Bioactive Compounds of Soybean: Benefits on Human Health

The soybean (Glycine Max. (L) Merrill) is a leguminous which originated from China and has been cultivated in this country for around five thousand years. It was considered for centuries the staple food of the countries of East Asia. In the West, its introduction was made experimentally in the Europe in 15th century. In the USA the first reports of cultivation of soybean date from 1765. Unlike East Asia, the USA soybean was initially cultivated as forage plant being used as a source of edible oil starting at 1915. A major technological progress for the use of soybean meal as protein source in nutrition was made in 1917, when Osborne and Mendel demonstrated that unheated soybean meal presents nutritional quality lower than that of heated soybean meal. Thus, the finding of the nutritional value of soybean meal as a feed for animal nutrition, coupled with growing demand for vegetable oils allowed the deployment of many industries for the processing of soybeans in the USA (Muller, 1981). In Brazil, the introduction of soybeans occurred in Bahia state, in 1882 (Bonetti, 1981). But the first statistics showing the use of soybean for grain production are from 1941. In this same year, the first soybean processing industry in the country was installed in Rio Grande do Sul (Teixeira, 2003). However, only from the 1960, soybean crop became important in the country, initially in the South where it showed better adaptation because of the similarity with regions of cultivation in southern United States. From the 70s, the soybean crop has evolved significantly in the cultivation states, not only in the south, but also in the middle western of Brazil. With the development of new cultivars adapted to different agro-climatic regions of the country, Brazil has become the second largest soybean producer in the world. Advances in new technologies for increased acceptability of soy proteins as human food occurred as result of protein deficiency worldwide, after the World War II. Since the 1950’s, USA and Canadian public research institutions worked on the development of soybean cultivars for human food use for export, mainly to Japan. In 1999, there were 16 breeding programs in public institutions working on soybean for human consumption (food-type). By

Extruded sorghum consumption associated with a caloric restricted diet reduces body fat in overweight men: A randomized controlled trial

This study aimed to evaluate the effect of sorghum intake on body composition and metabolic variables in overweight men. In a randomized controlled crossover study, 24 overweight men (25.6 ± 4.6 years) were randomly allocated into one of two treatments: extruded sorghum or extruded wheat. The study consisted of 2 periods of 8 weeks with at least 4 weeks of washout. Anthropometric, clinical and metabolic risk variables were assessed at baseline and at the end of each intervention period. Extruded sorghum consumption reduced body fat percentage and increased daily carbohydrate and dietary fiber intake when compared to wheat consumption. Also, sorghum increased the serum glutathione peroxidase concentration, but no difference was observed when compared to wheat consumption. Extruded sorghum demonstrated to be a good alternative to control obesity in overweight men.

Study of the physical and physicochemical characteristics of fruits of the licuri palm (Syagrus coronata (Mart.) Becc.) found in the Atlantic Forest of Minas Gerais, Brazil

The Atlantic Forest has species of native fruits, consumed fresh and processed, which have an important contribution to food sovereignty of families that consume it. This study examined the physical and physicochemical characteristics, proximate composition, concentration of carotenoids, vitamin C, vitamin E and minerals in the pulp and kernels of fruits of licuri (Syagrus coronata (Mart.) Becc.). Titratable acidity was analyzed by volumetric neutralization, soluble solids by refractometry, proteins by the micro-Kjeldahl method, lipids by gravimetry using soxhlet, dietary fiber by non-enzymatic gravimetry, carotenoids and vitamin C by HPLC-DAD, vitamin E by HPLC-fluorescence, and minerals by ICP-AES. Pulp were a source of Zn (0.95 mg 100–1), a good source of fiber (6.15 g 100–1), excellent source of provitamin A (758.75 RAE 100–1), Cu (0.69 mg 100–1), Fe (3.81 mg 100–1), Mn (3.40 mg 100–1) and Mo (0.06 mg 100–1). The kernel were a source of Fe (3.36 mg 100–1) and excellent source of Mn (6.14 mg 100–1), Cu (0.97 mg 100–1) and Mo (0.07 mg 100–1). The nutritional value and wide availability of licuri fruit make it an important resource for reducing food insecurity and improving nutrition of the rural population and other individuals who have access to it.