Effect of plasticizer type and amount on hydroxypropyl methylcellulose-beeswax edible film properties and postharvest quality of coated plums (cv. Angeleno).
The effect of the composition of hydroxypropyl methylcellulose (HPMC)-beeswax (BW) edible coatings on stand-alone film properties and on postharvest quality of coated 'Angeleno' plums was studied. Glycerol (G) and mannitol (M) were tested as plasticizers at two different plasticizer/HPMC ratios (100:1 and 300:1 molar basis). BW content was 20 or 40% (dry basis). An increase in G content increased film flexibility and vapor permeability (WVP), whereas an increase in M content enhanced film brittleness without affecting WVP. An increase in BW content reduced film flexibility and reduced WVP of only G-plasticized films. Coatings reduced plum softening and bleeding, but were not effective in reducing plum weight loss. At low plasticizer content, coatings reduced texture loss effectively. Low BW also lowered plum bleeding. Plasticizer type affected only ethanol and acetaldehyde contents without affecting the remaining quality parameters. Therefore, HPMC-BW coatings have the potential to extend the shelf life of plums. However, this effect depends on coating composition. Differences between coating and film performance indicate that data from stand-alone films may be used as a preliminary screening, but coating performance should be analyzed on coated fruit.
Determination of contamination pathways of phthalates in food products sold on the Belgian market.
As numerous studies have indicated that food ingestion is the most important exposure pathway to several phthalates, this study aimed to determine possible contamination pathways of phthalates in food products sold on the Belgian market. To do this, concentrations of eight phthalates (dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP)) were determined in 591 foods and 30 packaging materials. In general, the four most prominent phthalates in Belgian food products were DEHP, DiBP, DnBP and BBP. Special attention was given to the origin of these phthalates in bread, since high phthalate concentrations (especially DEHP) were determined in this frequently consumed food product. Phthalates seemed to occur in Belgian bread samples due to the use of contaminated ingredients (i.e. use of contaminated flour) as well as due to migration from phthalate containing contact materials used during production (e.g. coated baking trays). Also the results of the conducted concentration profiles of apple, bread, salami and two cheese types revealed the important role of processing - and not packaging - on phthalate contents in foods.
Orchard factors affecting postharvest stone fruit quality
Although stone fruit quality cannot be improved, only maintained, after harvest, little research has been conducted on the influence of preharvest factors on stone fruit postharvest quality and potential postharvest life. We believe that the maximum fruit quality for each cultivar can be achieved only by understanding the roles of preharvest factors in fruit quality. This article reviews the influences of orchard factors, such as mineral nutrition, irrigation, crop load, and fruit canopy position on fruit quality, market life potential, and internal breakdown (IB). The literature indicates that quality, market life, and IB are related to preharvest factors. Thus, there is a need to continue studying these factors to deliver high quality fruit to the consumer. In recent years the production of stone fruits has increased rapidly, but consumption has remained low at -2.7 k g . y e d per capita for nectarines and peaches and -0.6 kg.yearl per capita for plums and fresh prunes (U.S. Dept. of Agr., 1994). Surveys conducted to explain the low rate of consumption of stone fruits found that consumers were botheredmainly by lackofflavorand IB problems(Bruhnetal., 1991). Since production is still increasing, more attention must be given to the production and delivery of high-quality stone fruits to increase consumer demand. Studies have associated high consumer acceptance with high soluble solids concentration (SSC) in many commodities (Kader, 1994; Parker et al., 1991), but there are more factors involved, such as acidity (Kader, 1994; Peterson and Ivans, 1988), SSC/acidity ratio (Kader, 1994; Nelson, 1985; Rodan, 1988), phenolics (Robertson and Meredith, 1989), and volatiles (Romani, 1971). In peach (Pruws persica (L.) Batsch], plum (Prumrs salicina Lindel.), and nectarine [Prunus persica var. nectarine (L.) Batsch], there is limited information on the relationship between consumer acceptance and ripe fruit chemical composition (Claypool, 1977; Kader, 1994; Mitchell et al., 1990). Since we do not have enough information on this subject, we are not able to propose any quality standards without detailed studies to support them (Crisosto, 1994a). One important complex cause of quality deterioration and consumer complaints in apricots (Prunus armeniaca L.), peaches, nectarines, plums, and prunes (Pmnusdamesrica L.) is the presence of flesh browning, flesh mealiness, darkened pit cavity, flesh translucence, red pigment accumulation (bleeding), and loss of flavor (Crisosto et al., 1995a, 1995b; Mitchell and Kader, 1989). These symptoms result from IB, which is also called chilling injury, dry fruit, or woolliness. 1B normally appears during prolonged cold storage andor after ripening at‘room temperature following cold storage. This disorder is the main limitation to long-term storage and shipping to distant markets for IB-susceptible cultivars. There is little published information on the possible influence of preharvest factors on IB incidence (Claypool, 1977; Saenz, 1991). During the past I O years, increased research emphasis has been