Ultrasound pretreatment of protein could improve the angiotensin-I converting enzyme (ACE) inhibitory activity of hydrolysates and by alerting the structure of enzyme substrates. In this research the effects on ACE inhibitory activity and enzymolysis efficiency were explored under the optimum counter flow ultrasound (CFU) pretreatment conditions which obtained from our previous studies. The mechanism was studied by microstructure, nano-mechanical properties and secondary structures of wheat gluten (WG), which measured by scanning electron microscopy (SEM), atomic force microscopy (AFM), and flourier transform infrared spectrum (FTIR). The results showed that the CFU pretreatment resulted in significantly (P<0.05) higher value compared with control, the ACE inhibitory activity was increased by 29.8 % and the value of IC 50 was decreased by 36.92 %. CFU pretreatment increased the initial reaction rate by 9.58-20.27 % at a substrate concentration of 10-50 g/L, the K A was increased by 2.90 % and K M was decreased by 15.83 % compared to control. The microstructure revealed that the meshwork structure of WG was loosened and the surface roughness values of R a and R q were increased by CFU pretreatment. The nanomechanical analyses showed that CFU pretreatment redistributed the adhesion map and decreased the stiffness. The secondary structures were less ordered by CFU pretreatment. Intermolecular β-sheet of protein aggregation and random coil were increased, Intramolecular β-sheet, α-helix and β-turn were decreased. It was concluded that CFU pretreatment can remarkably improve the ACE inhibitory activity of hydrolysate and enzymolysis efficiency of WG confirmed by the changes of microstructure, nano-mechanical properties, and secondary structures.

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The study aims to determine drying of sweet potatoes using multifrequency ultrasound (US) pretreatments (20, 40, and 60 kHz) at three different infrared (IR) drying temperatures (60, 70, and 80°C) and evaluate the phytochemical and textural quality of the dried product. Drying time was significantly decreased in moderate US frequency (40 kHz) at 70°C with the increasing drying temperature. Comparing to the fresh samples, the dried samples showed the highest amount of phytochemical contents. The antioxidant activity of the samples increased especially at 60 kHz and 80°C, while US‐IR treatments shown a positive impact on total carotenoids contents and β‐carotene. For phenolic compounds, Ellagic acid and Rutin were quantified in higher amount while Quercetin‐3‐rhamnoside and Quercetin 3‐β‐D‐glucoside were two new compounds identified for the first time in sweet potatoes. FTIR spectra showed the successful synthesis of OH group and phenolics in samples treated with the US at 20 kHz. Practical applications This study investigated the effects of multifrequency ultrasound with different infrared drying temperatures. The study provides evidence that infrared drying application in synergy with ultrasonic pretreatments can improve drying efficiency and food quality much better than using each method alone. Total phenolic contents and total flavonoid contents remained stable at US 40 kHz and 60°C conditions. The findings showed that moderate ultrasound frequency (40 kHz) at 60°C improved phytochemical properties while antioxidant activities showed better preservation response at 80°C with 60 kHz. In addition, the samples treated with the same US treatment at 40 kHz showed less cell breakage in SEM analysis.

Purpose: To determine the effects of dates vinegar on blood biochemical and hematological parameters in type 2 diabetic subjects. Methods: Current research focused on fifty-five subjects having blood sugar more than126 mg/dL. Participants ingested dates vinegar (20 mL) daily into their normal diets for a period of 10 weeks. Glycated hemoglobin (HbA1c), fasting blood sugar (FBS), total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), creatinine (Cr), urea, complete blood count (CBC), alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), potassium and folate levels were analyzed before, after 5 weeks and after the experiment Results: Dates vinegar improved the blood concentrations of HbA1c (6.80 ±2.34 to 6.17 ± 2.14 (%)),

The effects of power ultrasound pretreatments on the degree of hydrolysis (DH), angiotensin-I-converting enzyme (ACE) inhibitory activity, amino acid composition, surface hydrophobicity, protein solubility, and thermal stability of ACE inhibition of rapeseed protein hydrolysates were evaluated. Ultrasonic pretreatments before enzymolysis in terms of power and exposure time increased the DH and ACE inhibitory activities over the control (without sonication). In this study, maximum DH 22.07% and ACE inhibitory activity 72.13% were achieved at 600 W and 12 min pretreatment. Compared to the hydrolysates obtained without sonication, the amino acid profile of ultrasound pretreated hydrolysates showed significant changes particularly in the proline content and hydrophobic amino acids with an increased rate of 2.47% and 6.31%, respectively. Ultrasound pretreatment (600 watts, 12 min) improved functional properties of protein hydrolysates over control by enhancing surface hydrophobicity and solubility index with an increased rate of 130.76% and 34.22%. Moreover, the stability test showed that the ACE inhibitory activity remains stable against heat treatments. However, extensive heat, prolonged heating time, and alkaline conditions were not in the favor of stability test, while under mild heat and acidic conditions their ACE inhibitory activities were not significantly different from unheated samples.