Impact of hexane defatting on characteristics of Patanga succincta L. powder and its application on nutritional improvement of biscuit stick

Impact of hexane defatting on physicochemical, oxidative stability and total volatile compounds of Bombay locust (Patanga succincta L.) powder ‘BL’ were studied. Defatted insect powder (F/BL) showed marked decrease in fat content (1.2%) with significantly (P≤0.05) higher protein content (78.7%), compared with those of BL (29.8% fat and 56.5% protein). Based on electrophoresis result, hexane defatting had no effect on peptide distribution of insect powders. F/BL had lower peroxide value with better oxidative stability (P≤0.05), while less variety of volatiles with more off-flavour compounds, particularly lipid oxidation and insect hormone odours, were observed from BL. F/BL was confirmed as an excellent source of amino acids and minerals. The physicochemical and sensory properties of F/BL fortified biscuit stick and the final products were determined. F/BL fortified biscuit stick showed a better acceptance, compared with those from BL at the same level used. Based on sensory characteristics, biscuit stick with 10% F/BL (F/BL-10) was selected and studied for its chemical composition and microstructure. F/BL-10 possessed more porous structure with higher protein and lower energy value, compared with those from 10% BL. Overall, defatted Bombay locusts could be an effective alternative protein source with excellent applicability to baked products, particularly biscuit stick.

Comparative study on different incorporation of olive oil and dill extract in fresh cheese

In the present study, a comparative analysis was undertaken on the possibilities of using olive oil in fresh spreadable cheese either emulsified or encapsulated. The changes in titratable acidity, active acidity and total Lactococcus count were recorded continuously throughout the storage period. At the end of the storage period, Lactococcus count in the samples with encapsulated oil were found to be slightly higher (7.7 and 7.8 log CFU.g-1 respectively) in comparison with the control sample (7.5 log CFU.g-1 ). A significantly higher content (P < 0.05) of unsaturated fatty acids (56.88 g per 100 g fatty acids) and a lower peroxide value of extracted fat (0.35 meqO2.kg-1 ) were found in the fresh spreadable cheese samples with 4% (w/w) encapsulated olive oil and extract of dill used as antioxidant in an amount of 0.003% (v/v). The addition of antioxidant (dill extract) further reduced oxidation process and enhanced cheese functionality. The sensory profile of the fresh cheeses, containing encapsulated oil, was better compared to the sensory profile of the products prepared with directly added olive oil (with or without added antioxidant).

Can Polyphenols be used as Natural Preservatives in Fermented Sausages?

This study was aimed at the investigation into the influence of polyphenols on fermented sausages produced with and without nitrite addition, during storage which lasted for 280 days. Three types of sausages were produced and formed the three experimental groups: C – the control – sausages of usual composition containing nitrites; N+P - sausages with nitrites and polyphenols; and P - nitrite-free sausages with added polyphenols. The proximate chemical composition of all groups was in the range with that of dry fermented sausages. P sausages contained 0.3 mg nitrites per kg, while C and N+P contained 54.8 mg/kg and 52.2 mg/kg, respectively. Polyphenol-enriched sausages had significantly lower peroxide and TBARS values than C sausages. In all sausages lactic acid bacteria counts reached 8.9-9.9 log cfu/g, but decreased during storage to 4.3-4.8 log cfu/g at the end of the storage period. Micrococcaceae counts remained stable: 3.5-3.9 log cfu/g. In P and N+P sausages a significantly lower number of Pseudomonadaceae was observed than in the control. The lightness of C and P sausages was similar (L=50.2 and L=49.5, respectively), while N+P sausages were darker (L=42.5). C and N+P sausages had similar redness (a*=14.5 and a*=13.2, respectively) and yellowness (b*=5.9 and b*=6.4, respectively), but the values which correspond to redness and yellowness were lower in P sausages (a*=8.0 and b*=4.6). Sensory characteristics of all products were found to be very similar. The flavour of polyphenol-enriched sausages was considered to be better. The most dominant polyphenol in sausages was kaempferol-3-O-glucoside followed by quercetin, luteolin-7-O-glucoside, catechin and syringic acid. Nitrite-free polyphenol-enriched sausages reached the same shelf life as conventional sausages containing nitrites did, which is a promising result implying that polyphenols might be used as natural preservatives and nitrite substitutes. Simultaneous use of nitrite and polyphenols is questionable due to their interactions which should be further studied.

Effect of electrochemically activated anolyte on the shelf life of cold stored rainbow trout

The sensory, physicochemical and microbiological properties of electrochemically activated anolyte and flake ice chilled rainbow trout (Oncorcynchus mykiss) packed in low-density polyethylene/polyamide bags were studied during storage for 20 days at 0-4°C. Significant reduction of the sensory assessed scores was found. The fish treated with ECA was assessed as satisfactory fresh to 15 days of storage. On this day, their sensory scores of the state of the eyes were higher (p* < 0.05) with 27.78%, skin appearance with 22.22% and taste of grilled trout with 18.75% respectively in comparison with flack ice chilled fish. After 20 days of storage the electrochemically activated anolyte treated rainbow trout characterised by 4.38% lower pH, 20.00% lower free fatty acids, 9.22 % lower peroxide value, 17.65% lower TBARS, 5.85% lower free α-Amino nitrogen, 19.66% lower total volatile based-nitrogen, 4.28% lower total viable counts on the skin and 2.90% in the muscle tissue, and 2.82% lower psychrotrophic count on the skin and 2.86% in the muscle tissue.The conclusion was made that the chilling of the rainbow trout with electrochemically activated ‎anolyte could contribute to prolong the shelf life by maintaining satisfactory organoleptic and ‎physicochemical properties to the 15th day at 0-4 °C.

Preparation of Novel High-Temperature Polyol Esters from Vegetable Oils

The aim of this work was to synthesize a high-temperature polyol ester from Jatropha oil. The synthesis process was accomplished via chemical modifications involving epoxidation to remove the double bonds in Jatropha oil, hydrolysis to add hydroxyl groups, and then esterification with pentaerythritol to form the saturated polyol ester. The high decomposition temperature 359°C of the polyol ester was determined by thermogravimetric analysis. The lower peroxide value 0.07 meq/kg and iodine value 0.02 mg I2/100 g of the polyol esters were also determined.

Modulation of longevity-associated genes by estrogens or phytoestrogens

Females live longer than males. We have shown that the higher levels of estrogens in females protect them against aging, by up-regulating the expression of antioxidant, longevity-related genes, such as that of selenium-dependent glutathione peroxidase (GPx) and Mn-superoxide dismutase (Mn-SOD). Both estradiol and genistein (the most abundant phytoestrogen in soybeans) share chemical properties which confer antioxidant features to these compounds. However, the low concentration of estrogens and phytoestrogens make it unlikely that they exhibit significant antioxidant capacity in the organism. Physiological concentrations of estrogens and nutritionally relevant concentrations of genistein activate the MAP kinase pathway. These, in turn, activate the nuclear factor kappa B (NF-κB) signaling pathway. Activation of NF-κB by estrogens subsequently activates the expression of Mn-SOD and GPx, but genistein is only capable of activating Mn-SOD expression. This could be due to the fact that genistein binds preferably to estrogen receptor β. The antioxidant protection is reflected in the lower peroxide levels found in cells treated with estrogens or phytoestrogens when compared with controls. The challenge for the future is to find molecules that have the beneficial effects of estradiol, but without its feminizing effects. Phytoestrogens or phytoestrogen-related molecules may be good candidates to meet this challenge.

New Concept of Co-Agents for Scorch Delay and Property Improvement in Peroxide Vulcanization

Peroxide cure is an important and widely used cure system for rubber. Several properties obtained via peroxide vulcanization are superior and not achievable with sulfur vulcanization, e.g.: aging resistance, no reversion and low compression set. However, other properties such as tensile strength and dynamic properties, are inferior to those of sulfur vulcanizates. The use of co-agents in peroxide cure leads to a certain extent to improvement in mechanical properties such as tensile strength. Nevertheless the properties are still inferior with respect to mechanical/dynamical properties of sulfur-cured articles. If these properties can be improved, the range of applications of peroxide cure in the rubber industry can be significantly broadened. Scorch is a common problem in peroxide cure, especially for injection molding and extrusion applications. Several additives can help to improve scorch safety, however, they always result in a lower peroxide efficiency, thus inferior vulcanizate properties. In the present study a new concept of co-agents for peroxide vulcanization is introduced. This new concept consists of the use of a combination of a bismaleimide type co-agent, like N,N′-m-phenylenedimaleimide (BMI-MP), and a sulfur containing compound, like dipentamethylenethiuram tetrasulfide (DPTT). This combination provides scorch safety and at the same time improves the mechanical properties of the vulcanizates. Within the bismaleimide type co-agents N,N′-p-phenylenedimaleimide (BMI-PP) provides better mechanical properties than BMI-MP. The concentration of co-agent and sulfur containing compound have a big influence on the scorch time and on the mechanical properties. Optimal properties are reached with 4 phr of co-agent and 0.7 to 0.96 phr of sulfur containing compound.

Erythrocyte vitamin E is oxidized at a lower peroxide concentration in neonates than in adults

Erythrocytes of neonates and adults were incubated with increasing concentrations of H2O2 in the presence of a catalase inhibitor and in the absence of glucose; the pattern of oxidation of vitamin E was analyzed in relationship to that of glutathione, hemoglobin, and polyunsaturated fatty acids (PUFA), and in relationship to hemolysis. The changes of these various parameters were analyzed in function of H2O2 concentration and in relation to incubation time, and were compared in erythrocytes from neonates and adults. In the absence of H2O2, erythrocyte glutathione and tocopherol levels were similar in neonates and adults, despite fourfold lower serum vitamin E level in neonates; alpha-tocopherolquinone, methemoglobin, and malonyldialdehyde (MDA) were not detectable. At 0.375 mmol/L of H2O2, glutathione was completely oxidized. Erythrocyte alpha-tocopherol remained unchanged up to 0.75 mmol/L of H2O2, then decreased linearly, with increasing H2O2 concentrations to 10% of its initial value at 1.5 mmol/L of H2O2 in erythrocytes from neonates, whereas those from adults required 2.0 mmol/L of H2O2 (P less than .05) for the same level of oxidation. The formation of alpha-tocopherolquinone appeared inversely related to the decrease of alpha-tocopherol. The incubation time did not influence the level of vitamin E oxidation. MDA was generated autocatalytically and resulted in hemolysis at 1.5 mmol/L of H2O2 in erythrocytes from neonates and at 3.5 mmol/L of H2O2 in erythrocytes from adults (P less than .001). After four hours of incubation, MDA reached a plateau at a greater level (365 +/- 46 nmol/L) in cells of neonates than in those of adults (208 +/- 37 nmol/L/mL) (P less than .001). Hemoglobin was oxidized in the same pattern in erythrocytes of neonates and adults, and 90% of it was oxidized at 0.625 mmol/L of H2O2. In conclusion, in the experimental conditions used, oxidation of glutathione precedes that of vitamin E, and tocopherol is the last antioxidant to be consumed before the autocatalytic generation of MDA. Differences in the pattern of vitamin E oxidation, MDA generation, and hemolysis in erythrocytes from neonates and adults may be due to a lower erythrocyte vitamin E-PUFA ratio in neonates.