Enrichment of Functional Properties of Ice Cream with Pomegranate By‐products

Pomegranate peel rich in phenolics, and pomegranate seed which contain a conjugated fatty acid namely punicic acid in lipid fraction remain as by‐products after processing the fruit into juice. Ice cream is poor in polyunsaturated fatty acids and phenolics, therefore, this study was conducted to improve the functional properties of ice cream by incorporating pomegranate peel phenolics and pomegranate seed oil. Incorporation of the peel phenolics into ice cream at the levels of 0.1% and 0.4% (w/w) resulted in significant changes in the pH, total acidity, and color of the samples. The most prominent outcomes of phenolic incorporation were sharp improvements in antioxidant and antidiabetic activities as well as the phenolic content of ice creams. Replacement of pomegranate seed oil by milk fat at the levels of 2.0% and 4.0% (w/w) increased the conjugated fatty acid content. However, perception of oxidized flavor increased with the additional seed oil. When one considers the functional and nutritional improvements in the enrichment of the ice cream together with overall acceptability results of the sensory analysis, then it follows from this study that ice creams enriched with pomegranate peel phenolics up to 0.4% (w/w) and pomegranate seed oil up to 2.0% (w/w) could be introduced to markets as functional ice cream. Enrichment of ice creams with pomegranate by‐products might provide consumers health benefits with striking functional properties of punicalagins in pomegranate peel, and punicic acid in pomegranate seed oil.     

Vehicle routing problem with stochastic travel times including soft time windows and service costs

This paper studies a vehicle routing problem with soft time windows and stochastic travel times. A model is developed that considers both transportation costs (total distance traveled, number of vehicles used and drivers' total expected overtime) and service costs (early and late arrivals). We propose a Tabu Search method to solve this model. An initialization algorithm is developed to construct feasible routes by taking into account the travel time stochasticity. Solutions provided by the Tabu Search algorithm are further improved by a post-optimization method. We conduct our computational experiments for well-known problem instances. Results show that our Tabu Search method performs well by obtaining very good final solutions in a reasonable amount of time.     

Synthesis and characterization of quaternized poly-alkyl α-chloroacetoxymethacrylates

Summary The homopolymers of ethyl α-chloroacetoxymethacrylate (ECAM) and t-butyl α-chloroacetoxymethacrylate (TBCAM) were quaternized homogeneously with trimethylamine (TMA) and N,N-dimethyldodecylamine in N,N-dimethylformamide (DMF). The ¹H-NMR measurments were used for the determination of the degree of quaternization (DQ) values. The DQ value of poly-ECAM quaternized with TMA at room temperature after 1 h was found to be 84 %, while the DQ value for poly-ECAM quaternized with N,N-dimethyldodecylamine was 37 %. Reactivity of poly-TBCAM was lower than that of poly-ECAM. The lower DQ value of TMA quaternized poly-TBCAM (19 %) is caused by steric hindrance in the vicinity of - CH₂Cl group due to bulky t-butyl group. Increasing reaction time, polymer concentration and temperature above a certain value for each polymer, resulted in crosslinked polymers. Solubility of the quaternized polymers is controlled by the substituents. Thermogravimetric analysis showed distinct differences in thermal stabilities which is controlled by the quaternary amine groups and ester substituents. Received: 19 February 2000/Revised version: 14 April 2000/Accepted: 14 April 2000