Taha Rababah

Effect of jam processing and storage on total phenolics, antioxidant activity, and anthocyanins of different fruits.

BACKGROUNDnFruits have been widely recognised as an excellent source of bioactive phenolic compounds. The purpose of this study was to evaluate the effect of jam processing of strawberry, cherry, apricot, fig and orange on the total phenolics, antioxidant activity and anthocyanins during 5 months of storage at 25 °C.nnnRESULTSnFresh strawberry had the highest contents of total phenolics (8503.1 mg GAE kg(-1) ) followed by cherry, apricot, fig and orange, respectively. Jam processing decreased the total phenolics, antioxidant activity, and anthocyanins of all fruits. Total phenolics of jam during storage decreased only in apricot, fig and orange. Fresh strawberry had the highest antioxidant activity (54.88% inhibition) followed by the other fruits. Antioxidant activity did not change in strawberry during jam storage, while there are reductions in the other fruits were observed. Fresh strawberry had the highest anthocyanins (2323.8 mg cya-3-glu kg(-1) ), followed by cherry and the other fruits, respectively. Results showed only a decrease of anthocyanins and pH in apricot and fig jams during 5 months of storage.nnnCONCLUSIONnDespite the reduction of these compounds in jam processing, it is considered a good method to maintain them during 5 months of storage.

Distribution, antioxidant and characterisation of phenolic compounds in soybeans, flaxseed and olives.

The distribution of free and bound phenolic compounds present in soybean, flaxseed and olive were investigated. The phenolic compounds were fractionated on the basis on their solubility characteristics in water, alcohol, dilute base and dilute acid. Reversed phase high pressure liquid chromatography (RP-HPLC) and mass spectrometry (MS) were used for identification of individual components of phenolic compounds. Antioxidant activity (AA%) of free and bound phenolic compounds was measured using the linoleic acid/β-carotene assay. The water-soluble phenolic compound fractions represented 68-81%, 50-72% and 46-56% of the total phenolic compounds measured in full-fat soybean, olive and flaxseed, respectively. Methanolic extraction of free phenolic compounds without heat, solubilised 21-56%, 42-62% and 34-51% of the total phenolic compounds measured in soybean, olive and flaxseed, respectively; methanol extraction of free phenolic compounds with heat solubilised a further 24-34%, 31-37% and 36-37% of phenolic compounds from soybean, olive and flaxseed, respectively. Further dilute alkali and dilute acid solubilised the remaining 10-40%, 1-21% and 12-29% of the total phenolic compounds from soybean, olive and flaxseed, respectively. Results indicated that the full-fat meals of soybean, flaxseed and olive showed higher antioxidant activity compared to defatted meals. RP-HPLC and LC-MS/MS profil1 for soybean, flaxseed and olive indicate two classes of phenolic compounds designated as free and bound phenolic compounds.

Anti-Oxidant, Anti-Diabetic, and Anti-Hypertensive Effects of Extracted Phenolics and Hydrolyzed Peptides from Barley Protein Fractions

This study was conducted to search for novel natural bioactive compounds (peptides and phenolic compounds) with hypoglycemic, antioxidant, and anti-diabetic potential from barley protein fractions and isolates. Protein isolate and globulin, prolamin, glutein-1, and glutein-2 fractions of barley flour were extracted from barley flour. Free and bound phenolic compounds were extracted from protein isolate and protein fractions. Protein isolate and protein fractions from barley were subjected to pancreatic hydrolysis to obtain peptides. Peptide and both free and bound phenolic compounds were subjected to determine antioxidant and their potential to inhibit the key enzymes relevant to diabetes and hypertension using in vitro models. The extracted phenolic from prolamin fraction and protein isolate revealed the highest content of total phenolics (2.0–2.4 mg/g), antioxidant activity (65–73%), angiotensin converting enzyme-inhibitory activity (73–87%), and α-amylase inhibitory activity (57–77%) as compared to that of other protein fractions. Hydrolysates of prolamin fraction exhibited the highest antioxidant activity (77.7%) and angiotensin converting enzyme-inhibitory activity (61.3%) as compared to all other protein fractions and protein isolate. Poor correlations were obtained between total phenolic content, antioxididant activity, ACE-inhibitory activity, and α-amylase inhibitory activity of phenolic compounds from protein fractions and isolate. On the other hand, positive correlations were obtained between antioxididant activities, angiotensin converting enzyme-inhibitory activity, and the degree of hydrolysis of peptides from hydrolyzed protein fractions and protein isolate. Our findings indicated that prolamin fraction and protein isolate were recommended to be used as hypoglycemic, antioxidant, and anti-diabetic ingredients as potential candidates in functional, nutraceutical, and pharmaceutical industries.

A review of phenolic compounds in oil-bearing plants: Distribution, identification and occurrence of phenolic compounds.

Over the last two decades, separation, identification and measurement of the total and individual content of phenolic compounds has been widely investigated. Recently, the presence of a wide range of phenolic compounds in oil-bearing plants has been shown to contribute to their therapeutic properties, including anti-cancer, anti-viral, anti-oxidant, hypoglycemic, hypo-lipidemic, and anti-inflammatory activities. Phenolics in oil-bearing plants are now recognized as important minor food components due to several organoleptic and health properties, and they are used as food or sources of food ingredients. Variations in the content of phenolics in oil-bearing plants have largely been attributed to several factors, including the cultivation, time of harvest and soil types. A number of authors have suggested that the presence phenolics in extracted proteins, carbohydrates and oils may contribute to objectionable off flavors The objective of this study was to review the distribution, identification and occurrence of free and bound phenolic compounds in oil-bearing plants.

Evaluation of the Nutraceutical, Physiochemical and Sensory Properties of Raisin Jam

This objective of this study was to evaluate the effect of jam processing of grape and raisin on the nutraceutical, physiochemical, and sensory properties. The results showed that fresh grape had the highest antioxidant activity, and total phenolic and anthocyanin content followed by grape jam, raisin, and raisin jam, respectively. No significant differences existed in soluble solids, pH, or firmness between grape and raisin jams. No significant differences in color parameters, ΔE, and chroma existed between grape and raisin jam. Descriptive sensory results showed minor differences in some sensory attributes between grape and raisin jams. In terms of consumer evaluation (9-point verbal hedonic scale and a 5-point just-about-right scale) the jams made from local raisins were parity with those from grape, despite small differences especially in whole raisin jam. Although raisin and other dried products are not traditionally considered as a raw material for jam processing, they have the same potential as fresh fruits.

Investigation of Natural Lipid–Phenolic Interactions on Biological Properties of Virgin Olive Oil

There is limited knowledge regarding the impact of naturally occurring lipid-phenolic interactions on the biological properties of phenolics in virgin olive oil. Free and bound phenolics were isolated via sequential methanolic extraction at 30 and 60 °C, and were identified and quantified using reversed phase high performance liquid chromatography, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), and gas chromatography. Decreased oleic acid concentrations and increased concentrations of palmitoleic acid, stearic, linoleic, and linolenic acids were observed in virgin olive oil after removal of free and bound lipid phenolic compounds. The presence of p-hydroxybenzoic acid and tyrosol bound to glycerides was determined via LC-MS/MS, which indicates natural lipid-phenolic interactions in virgin olive oil. Both free and lipid bound phenolic extracts exerted antiproliferative activities against the CRC1 and CRC5 colorectal cancer cell lines. The present work indicates that naturally occurring lipid-phenolic interactions can affect the biological properties of phenolics in virgin olive oil.

Effect of phenolic compound removal on rheological, thermal and physico-chemical properties of soybean and flaxseed proteins

This study aimed to investigate the effect of removal of phenolics on physico-chemical properties of protein isolates obtained from flaxseed and soybean. Proteins were isolated (I) from full-fat (F) and defatted (D) soybean (s) and flaxseed (f) using isoelectric precipitation. Free and bound phenolics were removed from the protein isolates. Thermal and gelation properties of protein isolates before and after removal of phenolics were investigated. Protein isolates from defatted soybean after removal of free and bound phenolics were showed a decrease in thermal stability of glycinin. For protein isolate from full-fat soybean, the results showed the removal of free phenolics increase thermal stability of glycinin with increase water holding capacity (WHC) and produce more viscous and less elastic gels as compared to protein isolate after removal of bound phenolics. Removal of free and bound phenolics from flaxseed protein isolates decrease thermal stability, WHC and viscoelastic properties as compared to protein isolate after removal of free phenolics.

Application of Hybrid Neural Fuzzy System (ANFIS) in Food Processing and Technology

AbstractnAdaptive neuro-fuzzy inference system (ANFIS) has emerged as a synergic hybrid intelligent system. It combines the human-like reasoning style of fuzzy logic system (FLS) with the learning and computational capabilities of artificial neural networks (ANNs). ANFIS has several applications related to food processing and technology. The first part of this review provides a brief overview and discussion of ANFIS including: the general structure and topology, computational considerations, model development and testing. In the second part, two detailed examples are explained to demonstrate the capabilities of ANFIS in comparison with other modeling methods, followed by a brief but comprehensive discussion of ANFIS applications in different food processing and technology areas. The applications are divided into five main categories: food drying, prediction of food properties, microbial growth and thermal process modeling, applications in food quality control and food rheology. In all applications, the performance of ANFIS is compared to other methods such as ANNs, FLS and multiple regressions when available. It is concluded that, in most applications, ANFIS outperforms other modeling tools such as ANNs, FIS or multiple linear regression. Finally, some application guidelines, advantages and disadvantages of ANFIS are discussed.

Preparation of mayonnaise from extracted plant protein isolates of chickpea, broad bean and lupin flour: chemical, physiochemical, nutritional and therapeutic properties

AbstractnThis investigation was aimed to study the molecular, physico-chemical, and biofunctional health properties of mayonnaise prepared using proteins isolated from broad bean, lupin and chickpea flour. Proteins were isolated from chickpea (CPPI), broad bean (BBPI) and lupin (LPPI) flour and assessed for molecular, physico-chemical, biofunctional, and protein yield. The highest water holding capacity, foaming stability, emulsion stability as well as protein yield and protein content of 44.0, 70.8, 37.5, 81.2, and 36.4, respectively were observed for BBPI. Mayonnaise prepared from the isolated plant proteins was evaluated for chemical composition, molecular properties of the protein subunits, and potential nutraceutical properties. Preparation of mayonnaise using BBPI or a mixture of either BBPI and CPPI or BBPI and LPPI showed superior values for lightness and lowered values for redness. Mayonnaise prepared from either BBPI or the BBPI and CPPI mixture showed the best antioxidant, antihypertensive and antidiabetic properties. The present study results indicated that the use of the BBPI and CPPI mixture can be a novel technological approach for the development of a mayonnaise with improved health promoting properties.

Molecular characterization and bio-functional property determination using SDS-PAGE and RP-HPLC of protein fractions from two Nigella species

This study aimed to investigate the molecular and bio-functional properties of protein fractions from Nigella damascena and Nigella arvensis, including the albumin, globulin, glutein-1, glutein-2 and prolamin fractions. Protein subunits were not observed in globulin and prolamin fractions. No peaks appeared in RP-HPLC chromatograms of globulin for either species. Two predominant peaks were observed in the RP-HPLC profiles of all protein fractions. Proteins separated by RP-HPLC have potential inhibitory and antioxidant activities in all fractions. Optimum ACE-inhibitory and antioxidant activities of proteins separated by RP-HPLC were observed in glutein-2 and albumin, respectively, for both species. For pepsin and combined pepsin-trypsin hydrolyses, the highest degree of hydrolysis (DH) was obtained in glutein-2 fraction of Nigella arvensis. Highest ACE-inhibitory activity of hydrolyzed protein fractions was found at 4h via pepsin hydrolysis in globulin fraction of Nigella damascena. Highest antioxidant activities of hydrolyzed protein fractions were found in glutelin-2 for both species.