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Structural, functional and nutritional properties of protein recovered from brown seaweed, S. latissima with alkaline solubilization/isoelectric precipitation as a function of different post-harvest stabilization methods were studied. The latter included freezing at −20 °C/-80 °C, oven-drying, sun-drying, freeze-drying and ensilaging. Also, the efficacy of freeze/thaw-aided precipitation (F/T) in improving protein recovery of the process was evaluated. The freeze-dried, oven-dried, and −20 °C frozen seaweeds resulted in significantly higher protein yield than the −80°C-frozen, sun-dried and ensiled biomasses. F/T increased protein precipitation and doubled total protein yield. Sun-drying and −20°C-freezing caused extensive protein degradation as revealed by SDS-PAGE and HP-SEC, while oven-drying altered the seaweed protein structure with less α-helices. Functional properties of the seaweed proteins were remarkably affected by stabilization condition and F/T, but nutritional value of the proteins was only dependent on stabilization method. Thus, to efficiently recover seaweed proteins, its post-harvest stabilization condition must be carefully chosen based on the final application of the proteins.

There is a strong need in animal production for sustainable protein sources used in feed. The aim of the present study was to evaluate the potential of the pH-shift process as a method to concentrate proteins from complex bone-rich herring (Clupea harengus) by-products. By-product parts (frame, head, guts), protein solubilization pH (pH 2.8 or 11.3) and separation g-force (800 or 8000 g) were varied. The findings revealed that protein recovery yields of up to 60% were obtained and that higher protein yield was obtained from the alkaline than the acid process. By-product part and g-force had no significant impact on protein yield. Protein levels reached in the concentrates were 75–80 % (dw basis). Protein concentrates contained a similar amino acid profile as have been reported for fishmeal, with ~40% essential amino acids and up to 7.8% and 2.8% of lysine and methionine. Residual levels of LC n-3 PUFA as well as calcium, magnesium, potassium and phosphorous were also found in the produced protein concentrates which could be an added value. Acid produced concentrates were particularly high in calcium potassium and phosphorous. Provided a careful evaluation, the pH-shift process could become a successful alternative to classic fish meal production for increasing the use of fish by-products for production of protein ingredients for feed.

On-time last-mile delivery is expanding rapidly as people expect faster delivery of goods ranging from grocery to medicines. Managing on-time delivery systems is challenging because of the underlying uncertainties and combinatorial nature of the routing decision. In practice, the efficiency of such systems also hinges on the driver's familiarity with the local neighborhood. This paper studies the optimal region partitioning policy to minimize the expected delivery time of customer orders in a stochastic and dynamic setting. We allow both the order locations and on-site service times to be random and generally distributed. This policy assigns every driver to a subregion, hence making sure drivers will only be dispatched to their own territories. We characterize the structure of the optimal partitioning policy and show its expected on-time performance converges to that of the flexible dispatching policy in heavy traffic. The optimal characterization features two insightful conditions that are critical to the on-time performance of last-mile delivery systems. We then develop partitioning algorithms with performance guarantees, leveraging ham sandwich cuts and 3-partitions from discrete geometry. This algorithmic development can be of independent interest for other logistics problems. We demonstrate the efficiency of the proposed region partitioning policy via numerical experiments using synthetic and real-world data sets.

The study was conducted to examine if crude enzymes (E) produced from Aspergillus niger by solid state fermentation could bio-transform carbohydrates, proteins, inositol phosphate (InsP) and saponins in soybean meal (SBM) under low moisture conditions. Two experiments were performed to determine the effect of mixing, moisture content, treatment time and E levels during enzyme hydrolysis. 1) A single replicate 2 3 full factorial screening design was used to determine the effect of the independent continuous variables time (30 and 70 min), moisture (350 and 450 g kg −1 DM), and the category variable mixing (i.e. effect of static conditions vs. active mixing (X3, S/M)) during the enzyme hydrolysis. 2) A three factorial central composite design (CCD) was used to study the effects of moisture content (316–484 g kg −1 DM), time of hydrolysis (16.4–83.6 min), and E content (0.32-3.68 g kg −1 SBM dry matter (DM)). The first experiment demonstrated that hydrolysis of InsP 6 was significantly affected by time (P < 0.01), moisture content (P < 0.0001) and static vs. mixing (P < 0.01). The hydrolysis of Bb-DDMP was also significantly affected by static vs. mixing (P < 0.05). The second experiment demonstrated that the hydrolysis of InsP 6 was significantly affected by time (P < 0.001), moisture (P ˂ 0.001) and enzyme content (P ˂ 0.01). The InsP 6 content was reduced 84% after 70 min, at a moisture content of 450 g kg −1 DM with the addition of 3 g enzyme kg −1 SBM DM, the InsP 5 -InsP 3 were not accumulated at these parameter settings. The hydrolysis of the saponin group Bb was explained by the enzyme square regressor (P < 0.001) and the interaction between moisture and enzyme (P < 0.001) reaching a maximum by the addition of 2.5 g enzymes kg −1 SBM DM at 484 g kg −1 moisture content. No significant effects on soluble protein and dietary fiber were observed. Mink were fed three diets containing 50% of the protein from SBM, SBM treated without enzymes or treated with enzymes. There was a trend of improved ash apparent digestibility in mink by the enzyme treatment (P = 0.07), but not for phosphorous. The apparent digestibility of protein and amino acids (AA) in mink was improved by the heat treatment used to inactivate the enzymes (P < 0.001), however, not by the enzyme treatment itself.

A recent focal point in research on the vehicle routing problem (VRP) is the issue of robustness in which customer demand is uncertain. In this paper, we conduct a theoretical analysis of the demand distributions whose induced workloads are as undesirable as possible. We study two common variations of VRP in a continuous approximation setting: the first is the VRP with time windows, and the second is the capacitated VRP, in which regular returns to the vehicle’s point of origin are required.

The content of zinc, iron, calcium and phytate in the 16 most consumed foods from 5 villages in a tropical rural area of Bolivia was analyzed. The fooditems were selected according to a completed food frequency questionnaire. Minerals were analyzed by atomic absorption and phytates by HPIC chromatography. The molar ratios of phytate:mineral are presented as indication of the mineral bioavailability. Within the analyzed food, quinoa is a potential source of minerals: zinc 3.65, iron 5.40 and calcium 176 mg/100 g; however, it also has the highest content of phytate 2060 mg/100 g. Cereals and legumes showed high concentration of phytates (from 142 to 2070 mg/100 g), roots and tubers have lower concentrations (from 77 to 427 mg/100 g). In general, both phytate contents and molar ratios Phy:Zn (phytate:zinc), Phy:Fe (phytate:iron) and Phy:Ca (phytate:calcium) in most of the analyzed foods were at levels likely to inhibit the absorption of these minerals. Significant positive associations (p < 0.01) were found between the level of phytate and minerals in food, for zinc (r = 0.714), iron (r = 0.650) and calcium (r = 0.415). The results compared to data from USA or from Bolivia showed some discrepancies, confirming the need for more reliable data for dietary evaluations and interventions.

In this paper, we present an algorithm for solving the sum-of-linear-ratios problem based on a linear relaxation of the objective function. Though there already exist linear relaxation algorithms for solving this problem, they all work on a space whose dimension increases with the number of ratios. When the number of ratios becomes large, these algorithms are unable to solve the problem efficiently. Our numerical experiments indicate that the proposed algorithm in this paper is superior to these existing algorithms when the number of ratios is large.

The fermented cereal-based gruel togwa is used as weaning food for children in Tanzania. Togwa is rich in minerals but these are often not available for uptake in the human intestine due to natural inhibitors, such as phytate (IP(6)). The yeasts Pichia kudriavzevii TY13, Hanseniaspora guilliermondii TY14 and TY20, isolated from Tanzanian togwa, and selected for high phytase activity in complex yeast medium YPD, were now studied regarding their ability to degrade IP(6) in maize-based model togwa. A modified constitutively high-phytase producing Saccharomyces cerevisiae BY80 and commercial Aspergillus ficuum phytase were included for comparison. In addition, a strain of Lactobacillus plantarum was included in the model-togwa set-up. All yeasts in the study grew and reached final cell density 1.5-2 log units higher than the start value. S. cerevisiae BY80 degraded 85% of the IP(6) in 48 h; the same degradation level as with A. ficuum phytase (89%). Of the togwa-isolated yeasts, P. kudriavzevii TY13 and H. guilliermondii TY14 showed strong phytate degradation in the model-togwa; 95% or more of the initial IP(6) was degraded after 48 h. This corresponds to a remaining level of 0.4 and 0.3μmol IP(6)/g dw. Co-inoculation with L. plantarum did not increase IP(6) degradation. Moreover, fermentation with P. kudriavzevii TY13 yielded a successive increase in inorganic phosphate (P(i)), from 0.7 to 5.4 mM, suggesting a phytase production in TY13 which is fairly insensitive to P(i) repression. The study shows that phytate in a model togwa is available for yeast phytase enzymes, and addresses the importance of strain selection for effectively degrading the phytate. Certain yeasts originating from togwa seem to have developed a natural high phytase production, and P. kudriavzevii TY13 and H. guilliermondii TY14 seem particularly well adapted to phytate degradation in togwa, and is our choice for further studies and strain improvement.

To evaluate lactic acid fermentation as a means to increase the availability of iron in carrot juice, two strains (Lactobacillus pentosus FSC1 and Leuconostoc mesenteroides FSC2), two types of carrot juice and two modes of fermentation were compared. Fermentation improved iron solubility up to 30 fold. The total mineral content and the yield of soluble iron differed between the two types of juice. Addition of pectolytic enzyme and cellulase further improved iron solubility in fermented juice by about 10%. L. pentosus FSC1 yielded the largest improvement in soluble iron, which was not simply a result of a decrease in pH. The concentration of soluble iron in Ln. mesenteroides FSC2 fermentation was linearly related to the major acids produced. Besides, the mineral inhibitor phytate was completely degraded in all the fermentations. Lactic acid fermentation strongly improves iron solubility in carrot juice. The level of improvement was strain specific and related to the produced acids rather than a simple pH effect. Composition of carrot juice and addition of viscosity-reducing enzymes also contributed to this improvement. Our study suggests that carrot juice with high mineral availability may be achieved by fermentation using selected starter cultures, substrate and process.

Using a combination of high-performance ion chromatography analysis and kinetic studies, the stereospecificity of myo -inositol hexakisphosphate dephosphorylation by the phytate-degrading enzyme P2 of Escherichia coli was established. High-performance ion chromatography revealed that the phytate-degrading enzyme P2 of E. coli degrades myo -inositol hexakisphosphate by stepwise dephosphorylation via d / l -Ins(1,2,3,4,5)P 5 , d / l -Ins(2,3,4,5)P 4 , d / l -Ins(2,4,5)P 3 or d / l -Ins(1,2,4)P 3 , d / l -Ins(1,2)P 2 or Ins(2,5)P 2 or d / l -Ins(4,5)P 2 to finally Ins(2)P or Ins(5)P. Kinetic parameters for myo -inositol pentakisphosphate hydrolysis by E. coli and wheat phytase, respectively, showed that the myo -inositol pentakisphosphate intermediate produced either by the phytate-degrading enzyme of wheat or E. coli are not identical. The absolute configuration of the myo -inositol pentakisphosphate isomer produced by the E. coli enzyme was determined by taking into consideration that wheat phytase produces predominantly the d -Ins(1,2,3,5,6)P 5 isomer (Lim, P.E., Tate, M.E., 1973. The phytases: II. Properties of phytase fraction F 1 and F 2 from wheat bran and the myo -inositol phosphates produced by fraction F 2 . Biochim. Biophys. Acta 302, 326–328). The data demonstrate that the phytate-degrading enzyme P2 of E. coli dephosphorylates myo -inositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via d -Ins(1,2,3,4,5)P 5 , d -Ins(2,3,4,5)P 4 , d -Ins(2,4,5)P 3 , Ins(2,5)P 2 to finally Ins(2)P (notation 6/1/3/4/5).

No difference in wheat phytase activity was observed when different types of acid were used to adjust the pH of wholemeal wheat flour suspensions to pH 5·0, the optimum for wheat phytase. When whole wheat bread was made without additives or after adjustment of the dough pH with acetic acid or lingonberry (traditional ingredients in bread making in Sweden), 64%, 96% and 83%, respectively, of the initial phytate was hydrolysed. A small but significant difference between breads with and without yeast or with deactivated yeast was found, indicating that yeast contributed some phytase activity under the conditions of bread making (pH 5·3–5·8 and 30–37°C). The optimum pH of yeast phytase was found to be 3·5. The isomers of IP 5 formed with purified wheat phytase or yeast phytase were studied using sodium phytate as substrate. Wheat phytase formed 1,2,3,4,5-IP 5 whereas yeast phytase formed 1,2,4,5,6-IP 5 . Determination of the isomers of inositol pentaphosphate demonstrated that the reduction in phytate levels in bread compared with wholemeal flour resulted from both wheat and yeast phytase activities.