Changes in the quality of flaxseed oil powder produced by incorporating with microcrystalline cellulose and thyme.

Flaxseed oil is a high nutrition oil, rich in ω-3 fatty acid, tocopherols and phenolic compounds. However, it is prone to oxidation due to its high unsaturation which needs pretreatments to be easily introduce to the market. In this study, flaxseed oil was converted to powder form by mixing with microcrystalline cellulose (MC) and thyme powder to produce flaxseed oil powder. For this purpose, 3 different levels of thyme powder (5%, 10% and 15% of oil) were mixed with oil, followed by mixing with different proportions of MC (50:50, 50:75, 50:100 (oil:MC)) and stored for 90 days at 25 °C and 4 °C. Results indicated that the total phenolic compounds (23.2-91.2 mg GAE/100 g), chlorophyll (9-63.6 mg/kg), and carotenoid (4.4-9.9 mg/kg) contents increased with the incorporation of thyme powder into the flaxseed oil on the first day in 25 °C and 4 °C. Also during 90 days storage, phenolic compound (21.8%), chlorophyll (32.5%) and carotenoid (24%) decreased in both 25 °C and 4 °C temperatures. The results confirmed that adding thyme powder to samples decreased acidity and peroxide value in compare with control. Using thyme as a natural antioxidant and also transforming the oil to powder form by MC increased the oxidative stability in compare with control. The produced high stable flaxseed oil powder has the potential to be used directly on food products like salads or to be used in different food formulations to fortify them with natural antioxidants and ω-3 essential fatty acids.

Preparation of egg white powder using electrohydrodynamic drying method and its effect on quality characteristics and functional properties.

This research investigated the effects of spray drying (SD, set at 180 °C), freeze-drying (FD, set at -35 °C), and electrohydrodynamic drying (EHD) with and without the foam-mat method on egg white. The configuration used in EHD was a wire-to-plate type at room temperature. The results showed no significant difference in gel hardness and WHC% (P ≥ 0.05). Also, the foam-mat EHD powders resembled the FD powders in microstructure, appearance, flowability, and absorption intensity of the Amide I and II bands. Furthermore, the foam-mat EHD (DC-) powder had the highest protein content (66.1%), enthalpy (-183.06 J/g), and foaming capacity (725%) (P < 0.05). This finding was proved by FTIR, Raman, and SDS-PAGE tests, which revealed the minor structural changes in proteins (peptide chain structure, Amide I, Amide II, α-helix, and ß-sheet). FD powder demonstrated good protein stability in zeta potential and foam stability tests.

Effects of roasting on alkylpyrazin compounds and properties of cocoa powder.

The volatile flavor compounds are the most important indicators of the quality of cocoa beans, among which pyrazines are considered as the main and key groups affecting the cocoa flavor. In cocoa processing, roasting is an important stage in the technical treatment of cocoa and has a significant impact on chemical properties of cocoa and its flavor. The present study aimed to assess the impact of roasting (temperature and time) on alkyl pyrazines, as key flavor compounds, via gas chromatography-mass spectrometry. Additionally, other properties, including color, polyphenols, chemical properties, and sensory attributes of cocoa powder were investigated. The results indicated that with the change in roasting time and temperature, these properties changed significantly. The cocoa powder roasted at 140 °C for 40 min had the highest browning index value (OD460/OD525), tetramethylpyrazine to trimethylpyrazine (TMP/TrMP) ratio, and sensory evaluation score and the lowest polyphenol content compared to the other samples.

Protection of navy-bean bioactive peptides within nanoliposomes: morphological, structural and biological changes.

This study aimed to produce bioactive peptides from navy-bean protein with alcalase and pepsin enzymes (30-300 min) and to load them into a nanoliposome system to stabilize and improve their bioavailability. The degree of hydrolysis and biological activities (scavenging of DPPH, OH, and ABTS free radicals, reducing power, and chelating metal ions) of navy-bean protein were affected by the type of enzyme and hydrolysis time. The average particle size (83-116 nm), PDI (0.23-0.39), zeta potential (- 13 to - 20 mV), and encapsulation efficiency (80-91%) of nanoliposomes were influenced by the type and charge of peptides. The storage temperature and the type of loaded peptide greatly affected the physical stability of nanocarriers and maintaining EE during storage. The FTIR results suggested the effect of enzymatic hydrolysis on the secondary structures of protein and the effective placement of peptides inside polar-regions and the phospholipid monolayer membrane. SEM images showed relatively uniform-sized particles with irregular structures, which confirmed the results of DLS. The antioxidant activity of primary peptides affected the free radical scavenging of loaded nanoliposomes. Liposomes loaded with navy-bean peptides can be used as a health-giving formula in enriching all kinds of drinks, desserts, confectionery products, etc.

Extraction of pumpkin peel extract using supercritical CO2 and subcritical water technology: Enhancing oxidative stability of canola oil.

In this study, subcritical water extraction (SWE) and the supercritical fluid extraction (SFE) methods were used for the extraction of pumpkin peel extract. Total phenolic content and carotenoid compounds of extracts were measured. The extracts were added to canola oil at a concentration of 400 ppm and were stored at 30 °C for 60 days. The peroxide, carbonyl and acid values of the oil samples were measured, then compared with 100 ppm of tert-butylhydroquinone (TBHQ) synthetic antioxidants. The results showed that the total phenol content of obtained extract by SFE (353.5 mg GA/100 g extract) was higher than by SWE (213.6 mg GA/100 g extract), while the carotenoid content was higher for obtained extract by SWE (15.22 mg/100 g extract) compared to SFE (11.48 mg/100 g extract). The result of oil oxidation showed that the oxidative stability of the oil containing the mixed extract (SFE-SWE) is higher than the separate extract, consequently showing higher performance in preventing oil oxidation compared to TBHQ.

The influence of three different types and dosage of alkaline on the inherent properties in cocoa powder.

Alkalization modifies the color and flavor of the cocoa products. The aim of the present survey was to determine how different types and dosage of alkaline relate to the color quality, total polyphenol amount and alkylpyrazine content of cocoa powder. Cameroon cacao beans were used to produce cocoa nibs. The nibs were alkalized with the solutions of NaOH, K2CO3, and NH4HCO3 at their different concentrations and combinations. The browning index (OD460/OD525) and alkylpyrazine content were changed significantly (p ≤ 0.01) with changing the type and the concentration of the alkali solution. The browning index, moisture, ash, and acid-insoluble ash content increased as the concentration of the alkali increased. In general, the not-alkaline products had more polyphenol and ratio of tetramethylpyrazine to trimethylpyrazine than the alkalized ones. Besides, the polyphenol and alkylpyrazine amounts decreased as the concentration of the alkali increased (p ≤ 0.01). At the same concentration, alkalization with a NaOH solution produced a higher polyphenol and alkylpyrazine content, but lower OD460/OD525 value than that with a K2CO3 solution. The samples with a high concentration of alkaline solution had the lowest ratio of monomer anthocyanins to yellow and brown polymers content (F1/F3) value.

Novel carriers ensuring enhanced anti-cancer activity of Cornus mas (cornelian cherry) bioactive compounds.

Cornusmas' bioactive compounds are powerful antioxidants. In this study, we evaluated the antioxidant activity of the encapsulated bioactive compounds of Cornus mas extract (CME) and its release in semi digestive condition via enteric coated nanocarriers (NCs). The two forms of CME, encapsulated into enteric coated nanocarriers (CME-NCs) and free CME, were studied to determine the effect of encapsulation on the stability of antioxidants. Then, their effect on cell cycle, cell viability and apoptosis of cancer cells were studied. The characterization analysis reported the mean particle size and zeta potential value of NCs equal to 22.7 ± 6.58 nm and -16 ± 5 mV. The results showed that CME-NCs could improve IC50 value 1.33 and 1.47 times more than the free CME after 24 and 48 h of incubation. These findings confirmed that CME-NCs could stop the cells proliferation in G1 phase, and caused apoptosis in cancer cell line HT-29.

Investigating the flavor compounds in the cocoa powder production process.

Flavor is one of the most important quality properties of cacao beans, playing a key role in the admissibility of cocoa products, such as cocoa powder. This study examined the industrial processes influencing the flavor of cacao beans. The Ivory Coast cacao beans were used after their alkaline treatment with potassium carbonate (up to pH 7.5-8) and being roasted at 115-120°C for 60-70 min. The volatile components were extracted using Likens-Nickerson simultaneous distillation-extraction (SDE) apparatus. The volatile compound profiles were identified by means of gas chromatography-mass spectrometry (GC-MS), as a result of which several compounds (alcohols, carboxylic acids, aldehydes, ketones, esters, and pyrazines) were recognized. Alkalization and roasting were shown to be two important steps in the cacao beans processing that can affect the final cocoa powder flavor. In addition, pyrazines and esters were two major groups of flavor compounds formed during the roasting stage by the Maillard reaction. The percentage of 2,3,5,6-tetramethylpyrazine was detected in the cacao beans equal to 0.5%. After the liquor pressing stage, tetramethylpyrazine increased to its highest amount (3%) in cocoa powder. It was found that the cocoa powder contained 2.69% of tetramethylpyrazine, 3.22% isobutyl benzoate, and 1.38% linalool. The highest percentage of increase in the mean amounts of 2,3,5,6-tetramethylpyrazine, isobutyl benzoate, and linalool were observed in the roasting stage, after which the percentages diminished.

Effects of drying, packaging, and temperature on the quality of fried onion slices.

Onion is used widely as a condiment for meat and other types of food in Iran. Because of the high sensitivity of this product to storage conditions and having not enough storage under controlled atmosphere (CA), the effects of drying method, packaging, and temperature during storage on thin slices of fried red Azershahr variety onion were investigated. To prepare this processed food with excellent organoleptic properties and useful in the food service industry onions were sliced (2 mm), deep-fried with corn frying oil in a batch fryer at 150 degrees C, and dried to a water content of 3-4% in a hot-air dryer at 70 degrees C for 24 h and a microwave system. Samples were packed in aluminum foil, which was purged by nitrogen gas, and cellophane-sealed with thermal sewing. Then these samples were kept for one year at laboratory temperature and in a freezer at -18 degrees C. During the storage time the moisture content, peroxide value, vitamin C content, total microbial count (TMC), and organoleptic characteristics of the samples were analyzed every 2 mo. The results of microbial analyses indicated that after 6 mo all of the samples had higher TMCs than the permission limits so the expiration date was set before that. The moisture contents and peroxide values showed a noticeable increase, probably due to seal failure, whereas vitamin C decreased up to 66% during storage. The loss of sensory properties was parallel to the microbial and chemical results. The findings revealed that the best sample was oven-dried, packed in aluminum foil under inert gas, and kept in a freezer (OAF) up to 6 mo.