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Abstract: Apricot kernels were roasted at various temperatures (120–180 °C) for 10 min and changes in the fatty‐acid profiles, oxidative stability, and antioxidant activity, as well as the total phenolic contents (TPC) of the oils and skin (seed coat), were monitored. Roasting has no obvious influence on profiles and contents of fatty acid, induction period (IP), browning index, TPC, and antioxidant activity (2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), 2,2‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid), (ABTS) and Oxygen Radical Absorbance Capacity (ORAC) of oils obtained from apricot naked‐kernel, but increases IP, TPC, and oxidative stability in oils obtained from apricot kernel with skin. All results in the present work demonstrated that thermal treatment accelerated the production and transference of alcohol‐soluble phenolics into the oil, and improved the oil oxidative stability. It is not Maillard reaction products but alcohol‐soluble phenolic compounds in skins that play a role in improving the oxidative stability and antioxidant activity of oils, and inhibition for primary peroxide production was more effective than secondary peroxide production at a low roasting temperature and a short roasting time. The present findings can advance knowledge on the conditions used for utilization of coproducts (skin) of apricot kernel and facilitate large‐scale production of stable oil against oxidation. [ABSTRACT FROM AUTHOR]

Quality parameters and volatile profiles were determined for Longwangmo apricot ( Prunus armeniaca L.) kernel oil prepared by cold pressing, heat pressing, and refining of sun-dried and baked apricot kernels. Quality parameters determined included peroxide value, acid value, fatty acids, and UV absorbance. The tested oils showed absorbance values at 232 and 268 nm of 0.70-0.85 and 0.20-0.38, respectively; peroxide values were 2.09-5.62 mmol O2/kg and acid values were 0.36-1.40 mg KOH/g. The major fatty acid composition found in the oils was oleic acid (70.29-71.25%) followed by linoleic (22.31-23.00%), palmitic (4.57-4.87%), stearic acids (4.57-4.87%), palmitoleic acid (0.62-0.71%), and α-linolenic acid (0.15-0.18%). The numbers and concentrations of volatile compounds in the oils ranged from 19-52 to 6172-23871 μg/g, respectively. Nine compounds were present, in different amounts, in all apricot kernel oils studied: benzaldehyde, 2-methyl-propanal, 2-methyl-butyl aldehyde, furfural, nonanal, methylpyrazine, 2,5-dimethyl-pyrazine, methoxy pyrazine, and 3-ethyl-2,5-dimethyl-pyrazine. The results of our present investigation revealed that the oil-producing process had significant influence on the volatile profiles of apricot kernel oil. In particular, the baked-pretreatment process may enhance the aroma of apricot kernel oil by increasing the number and quantity of volatile compounds. Practical applications: Apricot kernel oil has recently received attention because of its health and nutritional properties, with favorable fatty acid composition and biologically active compounds. The results showed that Longwangmo apricot kernel oil is suitable as an edible food oil and the baked-pretreatment process with cold pressing may lead to an oil with enhanced flavor. The baked (80°C)-pretreatment process with cold pressing is good oil-producing process for apricot kernel oil by increasing flavor. [ABSTRACT FROM AUTHOR]

In the actual industrial production process, the efficient biosynthesis and secretion of Monascus pigments (MPs) tend to take place under abiotic stresses, which often result in an imbalance of cell homeostasis. The present study aimed to thoroughly describe the changes in lipid profiles in Monascus purpureus by absolute quantitative lipidomics and tandem mass tag-based quantitative proteomics. The results showed that ammonium chloride stress (15 g/L) increased MP production while inhibiting ergosterol biosynthesis, leading to an imbalance in membrane lipid homeostasis in Monascus . In response to the imbalance of lipid homeostasis, the regulation mechanism of phospholipids in Monascus was implemented, including the inhibition of lysophospholipids production, maintenance of the ratio of PC/PE, and improvement of the biosynthesis of phosphatidylglycerol, phosphatidylserine, and cardiolipin with high saturated and long carbon chain fatty acids through the CDP-DG pathway rather than the Kennedy pathway. The inhibition of lysophospholipid biosynthesis was attributed to the upregulated expression of protein and its gene related to lysophospholipase NTE1, while maintenance of the PC/PE ratio was achieved by the upregulated expression of protein and its gene related to CTP: phosphoethanolamine cytidylyltransferase and phosphatidylethanolamine N-methyltransferase in the Kennedy pathway. These findings provide insights into the regulation mechanism of MP biosynthesis from new perspectives.IMPORTANCE Monascus is important in food microbiology as it produces natural colorants known as Monascus pigments (MPs). The industrial production of MPs has been achieved by liquid fermentation, in which the nitrogen source (especially ammonium chloride) is a key nutritional parameter. Previous studies have investigated the regulatory mechanisms of substance and energy metabolism, as well as the cross-protective mechanisms in Monascus in response to ammonium chloride stress. Our research in this work demonstrated that ammonium chloride stress also caused an imbalance of membrane lipid homeostasis in Monascus due to the inhibition of ergosterol biosynthesis. We found that the regulation mechanism of phospholipids in Monascus was implemented, including inhibition of lysophospholipids production, maintenance of the ratio of PC/PE, and improvement of biosynthesis of phosphatidylglycerol, phosphatidylserine, and cardiolipin with high saturated and long carbon chain fatty acids through the CDP-DG pathway. These findings further refine the regulatory mechanisms of MP production and secretion., Competing Interests: The authors declare no conflict of interest.

To achieve the accumulation of targeted secondary metabolites, microorganisms must adopt various protection mechanisms to avoid or reduce damage to cells caused by abiotic stresses, which formed from the changes of physical and chemical culture conditions. The protection mechanism of Monascus sp. to tolerate high-concentration ammonium chloride was analyzed by sequential window acquisition of all theoretical mass spectra-mass spectrometry proteomics in this work, and the results indicated that abiotic stresses caused by high-concentration ammonium chloride inhibited the synthesis of chitin and glycoprotein, leading to a decrease in cell wall integrity and, thus, affecting cell growth. At the same time, it also inhibited the complex enzyme III and IV activities of the mitochondrial cytochrome respiratory chain, leading to an increase in reactive oxygen species (ROS) levels. With the aim to respond to abiotic stresses, the cross-protection mechanism was implemented in Monascus , including self-protection of the Monascus cell by promoting synthesis of trehalose, a molecular chaperone that facilitates protein folding (such as heat-shock protein) and autophagy-related proteins, through not the enzyme protection system (superoxide dismutase, peroxidase, catalase, NADPH oxidase, and alternative oxidase) but the glutathione/glutaredoxin system, to maintain the intracellular redox state and then eliminate or reduce ROS damage to the cell. At the same time, an alternative respiratory pathway related to NADH dehydrogenase was activated to balance the material and energy metabolism.

Various Monascus bioactive metabolites used as food or food additives in Asia for centuries are subjected to constant physical and chemical changes and different Monascus genus. With the aim to identify enzymes that participate in or indirectly regulate the pigments and citrinin biosynthesis pathways of Monascus purpureus cultured under high ammonium chloride, the changes of the proteome profile were examined using sequential window acquisition of all theoretical mass spectra-mass spectrometry-based quantitative proteomics approach in combination with bioinformatics analysis . A total of 292 proteins were confidently detected and quantified in each sample, including 163 that increased and 129 that decreased ( t -tests, p ≤ 0.05). Pathway analysis indicated that high ammonium chloride in the present study accelerates the carbon substrate utilization and promotes the activity of key enzymes in glycolysis and β-oxidation of fatty acid catabolism to generate sufficient acetyl-CoA. However, the synthesis of the monascus pigments and citrinin was not enhanced because of inhibition of the polyketide synthase activity. All results demonstrated that the cause of initiation of pigments and citrinin synthesis is mainly due to the apparent inhibition of acyl and acetyl transfer by some acyltransferase and acetyltransferase, likely malony-CoA:ACP transacylase.

Distal tibiofibular syndesmosis injury (DTS) occurs frequently with ankle sprains. Current treatments pose several limitations including causing soft tissue irritation, bringing damage to fixation secondary to weight-bearing, and requiring follow-up surgeries. Here, we investigated the clinical effects of a new technique, titanium cable isotonic annular fixation, for the treatment of DTS injury. From January 2015 to June 2017, 36 patients with ankle fractures and DTS injuries had their fractures repaired with the titanium cable isotonic annular fixation system. Recovery was scored by the AOFAS ankle function score system. We also assessed the differences in ankle motion between healthy and operative joints, and recorded the complications. All patients recovered from surgery without any serious complications. We followed all the cases for 18-25 months with an average follow-up of 21.26±3.23 months. 12 months after the operation, X-ray images showed that the titanium cables were fixed in the correct position without any fracture or loosening. Additionally, no degeneration or traumatic arthritis was observed in the ankle joint. There were no incision or bone mineral density changes between the titanium fix and tibiofibular bones. Nearly all patients recovered well except for three who developed inflammation and infection. However, these three patients recovered following 1 week of intravenous antibiotics and local radiofrequency physiotherapy. According to the AOFAS scoring system, all patients achieved satisfactory recovery 12 months post operation. Our titanium cable isotonic annular fixation system has both the advantages of elastic and rigid fixations. It can restore isotonic strength of the distal tibiofibular joint, and its biomechanical performance approaches normal physiological function. After the operation, patients tolerated weight-bearing exercise and recovered joint mobility. Finally, there is no need to remove the distal tibiofibular implant after 12 weeks. Overall, it is a highly effective surgical method to treat DTS injury., Competing Interests: None.

Enterovirus 71 (EV71) is a neurotropic pathogen that can induce hand, foot and mouth disease in children. There is an appreciable mortality rate after EV71 infections. The mechanism of action of EV71 replication is not known. Recent work has identified some of cell factors of the host that participate in the synthesis of the RNA and proteins of EV71 (e.g., hnRNP K, reticulon 3 (RTN 3)). In that work, researchers used a competitive assay to show that hnRNP K can interact with EV71 5' UTR, which is required for efficient synthesis of viral RNA. Using a yeast two-hybrid system, other researchers demonstrated that RTN 3 interacts with the N-terminal domain of EV71 2C, which is crucial for replication of viral RNA. Here, we discuss recent work focusing on the molecular mechanisms of hnRNP K and RTN 3 in the synthesis of the RNA and proteins of EV71.