Volume 18, Issue 4

Monascus pigments (MPs), as secondary metabolites of Monascus , are microbial pigments which have been used for thousands of years. MPs are widely used in food industry as food pigments and preservatives, which have the stability of light resistance, high temperature resistance and acid-base change resistance. In addition, the antioxidant, antibacterial, antiviral and anti-tumor biological activities of MPs have also attracted people’s attention. Moreover, Due to the presence of citrinin, the safety of MPs still needs to be discussed and explored. In this paper, the production, biological activity, application in various fields and methods of detection and reduction of citrinin of MPs were reviewed, which provide new insights into the study and safe application related to human different diseases, medicines or health care products with MPs as active substances.

Morinda officinalis ( M. officinalis ) polysaccharides are valuable ingredients with various bioactive functions. This work aimed to investigate whether fermentation could enhance the bioactivities of M. officinalis polysaccharides. A strain of Bacillus sp. DU-106 was introduced to ferment M. officinalis . Two polysaccharides (namely NMP-1 and FMP-1) were isolated from raw M. officinalis and fermented M. officinalis , respectively. The structure, immunoregulatory, and antioxidant activities of NMP-1 and FMP-1 were investigated. Bacillus sp. DU-106 fermentation changed the monosaccharide composition and conformation of M. officinalis polysaccharides. After fermentation, FMP-1 dramatically stimulated IL-1β secretion in RAW 264.7 macrophages. In vitro , Bacillus sp. DU-106 fermentation of M. officinalis enhanced the DPPH radical, hydroxyl radical, and superoxide anion scavenging activities. In vivo , FMP-1 extended the lifespan and ameliorated oxidative injury of Caenorhabditis elegans . Collectively, Bacillus sp. DU-106 fermentation significantly enhanced the immunoregulatory and antioxidant activities of M. officinalis polysaccharides.

The present study was aimed to determine the impact of processing (dehulling or germination) on the structure and rheological behaviour of gruels made from sorghum, soybean and sesame. A rotational viscometer was used to determine the rheological parameters of gruels from these materials. Compared to each raw material, the processing presented a significant effect on the viscosity of the gruels. The power law model was better described the rheological behaviour of the gruels. All gruels were time-dependent fluids, except for germinated sorghum-based gruels. Most of them were thixotropic shear-thinning fluids, only germinated sorghum-based gruels are non-thixotropic shear-thinning fluids and those from dehulled soybean exhibited anti-thixotropic behaviour. The apparent viscosity of gruels decreased with temperature, fitting an Arrhenius relationship, with the activation energy ranging from 5973 to 27,674 J/mol. The rheological behaviour of these foods will helps to understand the behaviour of any products based on their mixture.

Blend of starch and polysaccharide is a secure and feasible modifying method for starch. Effects of konjac glucomannan (KGM) on pasting, retrogradation, rheological and structural properties of low-amylose rice starch were evaluated. KGM addition reduced the pasting temperature, breakdown and setback values, but raised the peak viscosity. When KGM concentration increased, the storage and loss moduli showed an upward trend. Fourier transform infrared spectroscopy (FTIR) showed redshifts at 3450 and 1640 cm −1 and suggested the formation of intermolecular hydrogen bond between KGM and starch molecules. X-ray diffraction (XRD) indicated that KGM decreased the relative crystallinity from 11.88 to 3.10%. Scanning electron microscopy (SEM) of KGM induced samples showed looser network structures, and confocal laser scanning microscopy (CLSM) detected less cloud-like blurry pastes surrounding around the starch ghosts. KGM addition suppressed the starch retrogradation. These results could be used to broaden the application of KGM in the food industry.

Chemical compounds are of great importance in the food, cosmetic and pharmaceutical industries. Nutritional components, the presence of secondary metabolites with antioxidant and antimicrobial activity, and physicochemical properties of pulp, seed and peel of Lorena avocado cultivars were studied. Antioxidant activity was evaluated by ABTS, DPPH and lipid peroxidation in pulp, seed and peel. 26 extracts was evaluated. The results confirmed that the fruit parts stabilize free radicals and inhibit lipid oxidation processes, with the highest values in seed and peel, due to their content of flavonoids, o-diphenols and phenols. The results of phytochemical screening, antioxidant capacity and antimicrobial activity, showed significant bioprospective advantage for the presence of flavonoids, condensed tannins and total phenols in the seed, peel and pulp of Lorena avocado cultivars. Avocado fruits are rich in bioactive compounds that can be used in functional food applications.

The purpose of this study was to investigate the effect of variety, ripening degree, and also fermentation process on the bioactive compounds of olives, and on the fatty acid compositions of olive oils. The highest oil content was determined in fermented green olives (70.02% in Gemlik variety; 66.87% in Ayvalık variety). The fermentation process caused a notable reduction in both total phenolic content (from 2558.30–2894.40 to 699.10–1087.00 mg/kg), and antioxidant activity values (from 81.46–81.20 to 26.00–63.75%) of green olives in brine. Verbascoside was identified as the main phenolic compound (1150.95–1311.25 mg/kg). It was observed that oleuropein, hydroxytyrosol, tyrosol, and rutin contents of olives decreased after fermentation process. Concerning the fatty acid compositions of olive oils, oleic (70.13–75.47% for Gemlik; 67.36–70.22% for Ayvalık) and linoleic acid (6.18–11.13% for Gemlik; 10.13–12.94% for Ayvalık) contents showed differences regarding variety and maturation degree. However, there are minor variations in fatty acid composition according to fermentation.

The spent coffee grounds (SCG) are one of the byproducts generated in large volume by the coffee industry. Thus, this study aimed to evaluate solvents and methods of extraction of bioactive compounds from SCG and optimize the process. The solvent and the extraction method had a significant effect on the extraction yield of the bioactive compounds. Through the extraction kinetics, it was verified that 90 min was a sufficient time for the recovery of phenolic compounds. In general, the pure solvents had a lower extraction yield than the ethanol/water mixture and the rise in temperature, along with an ethanol/water mixture, proved to be favorable to the extraction process. Under optimized conditions it was possible to obtain 9.15 (mg GAE/g SCG d.b ), 0.58 (mg QE/g SCG d.b ), 255.55 (g SCG d.b /g DPPH) and 0.042 (mM Fe(II)/g SCG d.b ) for TPC, flavonoids, antioxidant capacity (DPPH) and antioxidant capacity (FRAP), respectively.