Development of cantaloupe (Cucumis melo) juice powders using spray drying technology

Cantaloupes are a good source of carotenoids and vitamin C. Cantaloupe fruit juice powder containing vitamin C and β-carotene can be produced by spray drying. The objective of this study was to develop cantaloupe fruit juice (CJ) powder and to evaluate its nutritional and physical properties. Fresh cantaloupe fruits purchased from a local store were diced and juiced. CJ with 10% maltodextrin (MD) added was spray dried at inlet temperatures of 170, 180 and/or 190 °C. Three spray dried cantaloupe powders, including CJ dried with MD at 170 °C (CJP1), CJ dried with MD at 180 °C (CJP2), CJ dried with MD at 190 °C (CJP3) were analyzed for moisture, water activity, vitamin C, β-carotene, dissolution, and microstructure. The actual production rate of the cantaloupe juice powders was lower than the estimated production rate. CJP1 had (p < 0.05) higher moisture content and water activity than CJP2, and CJP3. Vitamin C content (mg/100 g, dry solids) was significantly (p < 0.05) higher in CJP1 (136.36 ± 5.84) than CJP2 (91.85 ± 5.23) and CJP3 (78.30 ± 1.96). The powder produced at inlet temperatures 170 °C had higher β-carotene content (μg/g) than that produced at 180 and 190 °C.     

Concentration of Stearidonic Acid in Free Fatty Acids Form from Modified Soybean Oil by Selective Esterification with Dodecanol

The concentration of stearidonic acid (SDA, 18:4 n-3) in free fatty acids (FFA) formed by selective esterification with dodecanol (lauryl alcohol) was studied. For this purpose, modified soybean oil (initial SDA content, ~23 %) was converted into its corresponding FFA by chemical hydrolysis. In a second step, the resulting FFA were esterified with dodecanol. Process variables such as the type of biocatalyst (lipase), substrate molar ratio and amount of lipase were evaluated. The best SDA concentration (58 %) and recovery (94 %) were attained by performing the esterification reaction for 4 h, with 1:1 molar ratio (dodecanol:FFA), and 5 % (w/w) Candida rugosa lipase as biocatalyst. It was observed that SDA was concentrated in the unesterified fraction.     

Lipase-Catalyzed Concentration of Stearidonic Acid in Modified Soybean Oil by Partial Hydrolysis

Stearidonic acid (SDA, 18:4 ω-3) content of modified soybean oil (MSO) containing?~25?% SDA, was increased by lipase-catalyzed hydrolysis. Four non-immobilized powdered lipases, Lipase AY 30 (Candida rugosa), Lipase G 50 (Penicillium camembertii), Lipomod? 34P-L034P (Candida cylindracea [rugosa]), Lipomod? 36P-L036P (Rhizopus oryzae), and an immobilized lipase, Lipozyme RM IM (Rhizomucor miehei) were assessed, at various incubation times, for their ability to hydrolyze MSO and specificity toward SDA. The SDA enriched products contained triacylglycerols (TAG), diacylglycerols (DAG) and monoacylglycerols (MAG). Lipase 34P-L034P exhibited specificity towards SDA, while Lipase AY was able to discriminate against it. The highest total SDA content (40.9?mol%) was obtained with Amano AY lipase at 4?h incubation (66.2?% hydrolysis). Unhydrolyzed TAG, 1,3-DAG, 2,3(1)-DAG, and MAG contained 37.7 (56.4 at the sn-2 position), 41.6, 51.5 (54.9 at the sn-2 position), and 49.9?% SDA, respectively. Amano AY lipase was also used to hydrolyze previously SDA-enriched TAG (48.7?% SDA) obtained from low temperature crystallization of MSO. The highest total SDA content (62.7?mol%) was obtained at 12?h incubation (85.9?% hydrolysis). The SDA contents of unhydrolyzed TAG, 1,3-DAG, 2,3(1)-DAG, and MAG were 58.7 (65.7 at the sn-2 position), 71.2, 70.2 (52.9 at the sn-2 position), and 59.4?%, respectively.     

Hybrid time slots sequencing model for a class of scheduling problems

This article presents a new model for the short‐term scheduling of multistage batch plants with a single unit per stage, mixed storage policies, and multiple shared resources for moving orders between stages. Automated wet‐etching stations for wafer fabrication in semiconductor plants provide the industrial context. The uncommon feature of the continuous‐time model is that it relies on time grids, as well as on global precedence sequencing variables, to find the optimal solution to the problem. Through the solution of a few test cases taken from the literature, we show that new model performs significantly better than a pure sequencing formulation and better than a closely related hybrid model with slightly different sequencing variables. We also propose a new efficient heuristic procedure for extending the range of problems that can effectively be solved, which essentially solves relaxed and constrained versions of the full‐space model. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Non-toxic poly(ethylene terephthalate)/clay nanocomposites with enhanced barrier properties

Motivated by the technological need for poly(ethylene terephthalate) materials with improved barrier properties together with the requirement for sustainability this study focuses on an eco-friendly sulfonated polyester as clay compatibilizer to facilitate polymer mixing during melt compounding. We demonstrate that the nanocomposites based on sulfonated polyester are a reliable alternative to their imidazolium counterparts, exhibiting enhanced properties (water vapor and UV transmission), without sacrificing the excellent transparency, clarity and mechanical strength of the matrix.     

Wet Fractionation of Hard-to-Cook Bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.) Seeds and Characterization of Protein,Starch and Fibre Fractions

A 2³ factorial design with four replicates of the central trial was used to evaluate wet-fractionation conditions for complete use of hard-to-cook (Phaseolus vulgaris L.) seeds. Tested variables were flour/water ratio (1:5, 1:7.5 and 1:10 w/v), pH (8, 9.5 and 11) and a soaking time (1, 2 and 3 h). The optimum conditions (1:10 w/v flour/water ratio; pH 8; and 1 h soaking time) were determined by the percentages of protein and starch recovery. Three fractions were obtained by the process: a protein isolate, starch fraction and fibrous residue. Isolate crude protein content was 73.03%; its in vitro digestibility was 76.7%, and its amino acids concentrations, except for methionine and cysteine, met essential amino acids requirements for preschool children and adults. Total starch content was 71.41% with an amylose content of 21.46% and an amylopectin content of 78.54%. Total dietary fibre in the fibrous residue was 42.12%, with 81.10% insoluble fibre and 18.91% soluble fibre. The protein isolate’s high protein content, the purity of the starch fraction and high proportion of insoluble fibre in the fibrous residues show wet fractionated hard-to-cook bean to be a promising source of functional ingredients with possible food industry applications.     

Regularized signal reconstruction for level-crossing sampling using Slepian functions

In this paper, we propose a method for efficient signal reconstruction from non-uniformly spaced samples collected using level-crossing sampling. Level-crossing (LC) sampling captures samples whenever the signal crosses predetermined quantization levels. Thus the LC sampling is a signal-dependent, non-uniform sampling method. Without restriction on the distribution of the sampling times, the signal reconstruction from non-uniform samples becomes ill-posed. Finite-support and nearly band-limited signals are well approximated in a low-dimensional subspace with prolate spheroidal wave functions (PSWF) also known as Slepian functions. These functions have finite support in time and maximum energy concentration within a given bandwidth and as such are very appropriate to obtain a projection of those signals. However, depending on the LC quantization levels, whenever the LC samples are highly non-uniformly spaced obtaining the projection coefficients requires a Tikhonov regularized Slepian reconstruction. The performance of the proposed method is illustrated using smooth, bursty and chirp signals. Our reconstruction results compare favorably with reconstruction from LC-sampled signals using compressive sampling techniques.