Mónica Ihl

Natural Additives in Bioactive Edible Films and Coatings: Functionality and Applications in Foods

Incorporation of natural additives to active packaging systems or biopolymer-based edible films can modify the film structure and, as a result, modify their functionality and application to foods. This paper reviews the effect of the incorporation of natural additives from plant extracts or their isolated active compounds and vitamins on the functionality of edible films and the application of these films to foods. The final functionality of edible films is related to their bioactive properties (such as antioxidant, antimicrobial, and antibrowning activities) and functional properties (such as barrier to oxygen, carbon dioxide, and UV–vis light); water vapor permeability; tensile stress; elongation at break; and physical properties (such as opacity and color). Several categories of natural antioxidants found in plant, spices, and herbs (organic acids, plant natural extracts, and plant essential oils) have been incorporated into edible films and coatings, resulting in an improvement of the bioactive properties of the films. However, a wide range of plant natural sources with bioactive properties has not yet been characterized with respect to their ability to be applied directly on foods and used to develop active packaging or biopolymer-based edible films for preserving and adding value to foods. In addition, in vivo studies of the use of bioactive films to preserve the quality, shelf life, and nutritional value of foods remain limited.

Effect of immersion solutions on shelf-life of minimally processed lettuce

Abstract Prior to detailed quality and physiology evaluations, different immersion solutions (SIs) were analysed by means of a nontrained sensory panel. Each SI (calcium chloride, pectin, potassium sorbate, garlic extract and citric acid) was analysed at three concentrations. Based on at least 70% acceptance, the best mixed SI ( P

Substrate Specificity of Chlorophyllase from Different Plants

Abstract The activity of chlorophyllase (chlorophyll-chlorophyllido-hydrolase, EC 3.1.1.14) extracted from six different species was compared with enzyme extracted from leaves of Tree of Heaven. The chlorophyllase activity from Swiss chard was similar to the Tree of Heaven enzyme, all the others were less active or inactive. We tested the substrate specificity with bacteriochlorophyll a, chlorophylls a and b. pheophytins a and b and also the synthetic pig ments Zn pheophytins a and b and Zn pyropheophytin a. The natural pigments were the best substrates, but the Zn derivatives were also hydrolysed, except Zn pyropheophytin a which was accepted only by the enzyme extracted from the leaves of Tree of Heaven.

ARVEJAS (Pisum sativum) DE VAINA COMESTIBLE "SUGAR SNAP": ANTECEDENTES Y COMPORTAMIENTO EN EL SUR DE CHILE

A B S T R A C T Sugar snap peas (Pisum sativum L.) are edible-podded peas that, unlike snow (Chinese) peas, have thick pod walls. They are the result of the combination of at least six recessive genes controlling pod and grain traits, and two others are being incorporated in modern cultivars. Sugar snap peas may be consumed fresh or frozen, and are highly appreciated in the United States and other countries. Six genotypes from the USA were evaluated at two locations in La Araucania Region in southern Chile in 2004 and 2005. Most sugar snap varieties showed yields similar to a freezable cultivar used as a check. Yield differences among sugar snap varieties were small and inconsistent; however, cv. Sweet Ann performed relatively well and showed the best freezing quality. Over 15 t ha -1 of pods were obtained under favorable conditions, suggesting that yields around 10 t ha -1 are quite achievable commercially. All varieties presented, at variable levels, suture on both dorsal and ventral sides of the pods. A mild frost (-2 °C), harmless to the plant, may also deteriorate the appearance of the pods. Sugar snap peas are a delicate produce and, if well managed, can be a sound option to diversify Chilean horticultural offer.