Antioxidant activities of extracts from selected culinary herbs and spices

Recent advances on polysaccharides, lipids and protein based edible films and coatings: A review.

Lipid oxidation is important to food manufacturers especially when they increase unsaturated lipids in their products to improve nutritional profiles. Unfortunately, the number of antioxidants available to food manufacturers to control oxidative rancidity is limited and the approval of new antioxidants is unlikely due to economic barriers in obtaining government approval for new food additives. Therefore, new antioxidant technologies are needed for food oils. This paper reviews the current knowledge of lipid oxidation in foods with emphasis on how physical properties of food systems impact oxidation chemistry. In particular, the role of association colloids in bulk oils on lipid oxidation chemistry is discussed in an attempt to understand mechanisms of oxidation. Increasing the understanding of how physical properties impact lipid oxidation could lead to the development of novel antioxidant technologies that not only protect the oil against oxidation and increase shelf-life but also allow food manufacturers to include more nutritionally beneficial fatty acids in their products.

http://nfscfaculty.tamu.edu/talcott/courses/FSTC605/Papers%20Reviewed/Lipid%20Oxidation%20and%20Bulk%20oils.pdf

Role of Physical Structures in Bulk Oils on Lipid Oxidation

Background An increasing awareness among consumers regarding the healthy lifestyle have prompted research on novel techniques of prolonging the shelf life of food products without the necessity of using preservatives. Thanks to their ability to improve global food quality, edible films and coatings have been particularly considered in food preservation. Changing mechanical and barrier properties depending on the main component in the biopolymer matrix caused an increasing interest in composite structures, which enable to explore the complementary advantages of each component as well as to minimize their disadvantages. Scope and approach This review discusses the potential food applications of emulsified edible films and coatings. The materials, preparation methods, and physical properties are also presented. Lipids are usually added to edible films and coatings to impart hydrophobicity and thereby reduce moisture loss. A very wide range of lipid components is available including natural waxes, resins, acetoglycerides, fatty acids, and petroleum-based, mineral and vegetable oils. The emulsification process of the lipid phase in the aqueous phase is necessary prior to the coating application. Key findings and conclusions Emulsion-based edible films and coatings find application in fresh and processed food products, fruits and vegetables, cheeses, meat, sausages and bakery products. Composite emulsion-based edible materials produced from hydrocolloids and lipids result in better functionality than films produced with one component, especially with respect to their water barrier properties. In general, more research is needed to improve application processes of emulsion-based edible materials, especially sensory aspects, to be appropriate for each product.

Food applications of emulsion-based edible films and coatings

Strategies for designing novel functional meat products.

Edible coatings made of whey protein isolate (WPI), pea starch (PS), and their combinations with carnauba wax (CW) were prepared and characterized. WPI combined with CW formed stable emulsion while PS with CW formed unstable emulsion and both formulations produced non-homogeneous films. Addition of PS to WPI: CW combination at the ratio of 1: 1: 1, respectively, resulted in stable emulsion and homogenous films. The emulsion PS: WPI: CW (1: 1: 2) was stable and formed a continuous film but had less homogenous droplets size distribution when compared to 1: 1: 1 film. Combined films had a reduced tensile strength and elongation compared to single component films. WPI : CW (1: 1) films had higher elastic modulus than the WPI films, but the modulus reduced by the addition of PS. All the coating formulations were effective in preventing oxidative and hydrolytic rancidity of walnuts and pine nuts stored at 25 °C throughout the storage (12 d) but were less effective at 50 °C. Increasing the concentration of CW from 1: 1: 1 to 1: 1: 2 in PS: WPI: CW formulation did not contribute in further prevention of oil rancidity at 25 °C. Using of PS: WPI: CW (1: 1: 1) coating on both nuts significantly (P < 0.05) improved their smoothness and taste but the PS: WPI: CW (1: 1: 2) coatings imparted unacceptable yellowish color on walnuts.

Practical Application:  Edible coating of walnuts and pine nuts by whey protein isolate, pea starch, and carnauba wax reduced the oxidative and hydrolytic rancidity of the nuts and improved sensory characteristics.

Characterization of Edible Coatings Consisting of Pea Starch, Whey Protein Isolate, and Carnauba Wax and their Effects on Oil Rancidity and Sensory Properties of Walnuts and Pine Nuts

Effect of heating and processing methods of milk and dairy products on conjugated linoleic acid and trans fatty Acid isomer content.

The antioxidant activities of water and alcohol extracts of the flowers of chamomile (Matricaria aurea Schultz) and the seeds of anise (Pimpinella anisum L) and dill (Anethum graveolens L) were investigated. The extracts showed marked antioxidant activity in both linoleic acid and liposome model systems. This indicates that the extracts could be used as antioxidants in fat-containing foods. The water extracts of chamomile flowers and dill seeds showed higher antioxidant activity than butylated hydroxyanisole, whereas the antioxidant activities of the alcohol extracts of all three plants were lower. The water extracts showed higher antioxidant activity than the corresponding alcohol extracts. The antioxidant activity of both water and alcohol extracts decreased in the order chamomile flowers > gtill seeds > gtnise seeds. The extracts also showed good free radical-scavenging activity, indicating that they act as hydrogen donors. Copyright © 2004 Society of Chemical Industry

Antioxidant activity of water and alcohol extracts of chamomile flowers, anise seeds and dill seeds

Detection of olive oil adulteration with some plant oils by GLC analysis of sterols using polar column

A field study was conducted at two locations (Jordan valley and Al-Jubeiha) with different rainfall levels, altitudes and temperature ranges. The study was established to evaluate the optimum planting density, nitrogen (N) form and irrigation level to attain the best quality of lettuce crop in terms of minimum nitrate (NO 3 ) content and to minimise the impact on the environment. Seeds of 'Amar' lettuce were sown 1 month before transplanting. Three forms of N fertiliser (Ca(NO 3 ) 2 , (NH 4 ) 2 SO 4 and CO(NH 2 ) 2 ) were applied at three times at a total rate of 100 kg N ha -1 . Three in-row spacings (15, 20 and 25 cm) were assigned. Two irrigation levels were applied: level 1 had twice the amount of irrigation water as level 2, which was achieved by doubling the number of irrigation lines. The results indicated that N form significantly increased both N and NO 3 contents. Ca(NO 3 ) 2 was the most effective in increasing the N and NO 3 contents in lettuce leaf tissues, followed by CO(NH 2 ) 2 and then (NH 4 ) 2 SO 4 . The outer leaves (green colour) had about five times the NO 3 content of the inner leaves (pale yellow colour). However, the effect of N form on production, total N absorption and N recovery was significant in the following order: (NH 4 ) 2 SO 4 > Ca(NO 3 ) 2 > CO(NH 2 ) 2 . Increasing the plant spacing resulted in a significant increase in N and NO 3 contents in the lettuce leaves.

Khalid Al-Ismail

Papers

Characterization of Edible Coatings Consisting of Pea Starch, Whey Protein Isolate, and Carnauba Wax and their Effects on Oil Rancidity and Sensory Properties of Walnuts and Pine Nuts

Effect of heating and processing methods of milk and dairy products on conjugated linoleic acid and trans fatty Acid isomer content.

Antioxidant activity of water and alcohol extracts of chamomile flowers, anise seeds and dill seeds

Detection of olive oil adulteration with some plant oils by GLC analysis of sterols using polar column

Nitrate content in lettuce (Lactuca sativa L) heads in relation to plant spacing, nitrogen form and irrigation level