Chemical, microbiological and sensory evaluation of a dried salted product produced from sardines (Sardinops caerula) and cereals.

The chemical, microbiological and sensory stability of a dried salted product prepared from sardines and cereals was evaluated during a 12-week storage period. The product is named NUTRIPEZ and was produced in 20 kg/lots, both with and without smoke treatment. The product was stored under both tropical and room conditions in Mexico City, and packaged in two types of flexible packaging. Rancidity analyses were done by the peroxide value, TBA test and sensory evaluation. The results demonstrated that both the smoking of the product and the cellopolyal packaging, offered the best protection against oxidation.     

Impacts of Oil Types and Storage Conditions on Milk Fat Quality of Strained Yogurt Immersed in Oil

To maintain strained yogurt freshness, it was shaped into balls (3–3.5 cm diameter), completely immersed in oil, and stored at refrigerated or ambient temperature for 6 months. The impacts of immersing strained yogurt in oil on the topped oil and product's final quality of lipids including fat oxidation, lipolysis, cholesterol oxidation, and conjugated linoleic fatty-acid content (CLNA) (i.e., as freshness indicators), during storage under various storage conditions, were evaluated. Peroxide value (PV), 7-keto-cholesterol, free fatty acids (FFA), and CLNA content were also determined. When stored in light, FFA of strained yogurt immersed in olive or corn oil increased from 0.44 to 1.29 and from 0.12 to 0.58, respectively. Olive oil-topped and corn oil-topped samples exposed to light had 48.9 and 7.9 (meq O₂ kg⁻¹) PV, respectively. Similar trends were reported for strained yogurt fat during storage for up to 6 months. Storage conditions showed little to no effects on the rate of fat and cholesterol oxidation, fat lipolysis, and CLNA content. Strained yogurt freshness indicators were maintained during the extended storage duration without refrigeration. The freshness indicators have a significant impact on enhancing consumer preference of strained yogurt.     

Development of an intermediate moisture food from bean (Phaseolus vulgaris L.)

Beans consumption has been associated to reduction on chronic, non transmissible, diseases development. Generally, its consumption is less to the recommended and it is done principally as whole grain dishes. To increase the consumption, there is an especial interest in the use of new products. The main goal of this research was to design intermediate moisture bean purees (IMP) using soaked, cooked and grained Tortola bean, removing an important testa portion. In preparation of IMP two moisture levels, 25 and 30%, and two glycerol levels, 10 and 15%, were studied. Purees were preserved at ambient temperature (20 +/- 2 degrees C) for 30 days. Proximal analysis, phytate content and trypsin inhibitors were determined in the original non processed purees. IMPs were analyzed at preparation time and after 15 and 30 days of storage for moisture content, pH and water activity. Besides, microbiological analysis for total plate count on aerobic mesophile microorganisms, molds and yeast, total colifoms, fecal coliforms and Staphylococcus aureus, was carried out. Global quality and sensory acceptance was also determined. IMPs presented a(w) values between 0.800 and 0.844, a pH between 6.20 and 6.24 and the microbiological counting was negative or far below the accepted limits for more strict foods. IMPs presented good qualifications for global quality and were well accepted. Sensory parameters maintain their values during storage, except for color that in treatment with 30% moisture and 10% glycerol showed a light darkening. It is possible to elaborate intermediate moisture bean puree, with low level of antinutritional compounds, good quality and sensory acceptance and with adverse conditions for the development of food safety importance microorganisms.     

Finished oil handling and storage

A finished oil is defined as that fat or oil product ready for use alone or as an ingredient without further processing. It represents the culmination, and carries the costs, of all the processing steps required to present it for use in its final desired form. The goal of finished oil handling and storage is to maintain the quality obtained through previous processing. Possible effects on quality through exposure to air, moisture, light, storage temperature, storage times, type of container, and physical movement of product are discussed. Also included will be a discussion of bulk handling of edible oil products.     

Fish silage from shrimp by catch fish: I. Preparation and biological evaluation

Fish silage was prepared from some fish species of the shrimp by-catch caught in Golfo Triste, Carabobo, Venezuela. Fish were ground until a particle size that would guarantee the liquefaction process was achieved. The process was accelerated by the incorporation of a 3.5% w/w acid mixture, formed by diluted sulfuric acid (1:3) and concentrated formic acid, in a proportion of 1:4. The silage process occurred spontaneously at room temperature during 17 days. Chemical, physical and microbiological tests were conducted in order to characterize both the raw material and the final product. The raw material used had adequate levels of freshness, so that it was suitable for use, thus producing a first-grade silage. A first biological evaluation was carried out in rats in order to estimate the protein quality of the silage by means of certain biological parameters such as PER, NPR and apparent digestibility percentage of the protein. The results of the first experimental period demonstrated that the fish silage protein was of optimal quality, since the biological response in rats was similar to that of the control group fed the casein diet.     

Preparation and evaluation of fish portions from shrimp by-catch

Fish portions were obtained from a mixture of fish flesh from shrimp by-catch. Physical, chemical, microbiological and sensory tests were done to evaluate quality of raw materials, formulations and processing conditions. Several technological procedures proved to be feasible for this product. Stability of frozen products for four months was determined by physical, chemical and microbiological tests, the results of which indicated its stability during the study period. Findings of our study, therefore, suggest the potential of shrimp by-catch for the preparation of fish portions in view of its high acceptability and simple processing technique, by using marine resources not fully utilized at present.     

Influence of blanching treatment and drying methods on the drying characteristics and quality changes of dried sardine (Sardinella gibbosa) during storage

The aim of this study is to examine the drying characteristics of blanched and unblanched sardine during indoor and open sun drying processes. Changes in temperature and relative humidity of the air during drying were recorded. The color, peroxide value (PV), thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA) content, fatty acid composition, and sensory attributes of dried samples were also evaluated once a month for 5 months of storage. High drying rates were obtained in all samples at the start of drying and then decreased with increasing drying time. The highest drying rate and effective water diffusivity (D_eff) were observed in blanched sardine during open sun drying. Blanching treatment slowed down the FFA progression during product storage but adversely affected the color, PV, and TBARS content as well as sensory properties. Although sardine dried for a longer time under indoor drying conditions, it attained a stable moisture ratio that was lower than in open sun-dried samples. Indoor drying produced a quality stable product with less lipid oxidation and the desired moisture content, higher polyunsaturated fatty acids and sensory properties. Blanching treatment negatively affected the fish quality and is therefore not recommended for commercial sardine drying.     

Elaboration of a dried-salted and smoked product using aquaculture species

The purpose of this work was to adapt the procedure developed at the Instituto Nacional de la Nutrición Salvador Zubirán (INNSZ) for the conservation of the sardine to aquaculture species such as carp (Ciprinus carpio) and tilapia (Tilapia sp). The mixtures were designed on the basis of the chemical score method. The preparation of the patties included different fish presentations, and two methods were evaluated in order to obtain fish pulp. In the formulation of the final product, defatted soy, maize and wheat flour were included, as well as three different mixtures of condiments, which were then compared to the original formulation based on sardine. The raw materials and final products were subjected to sensory evaluation and to a shelf-life study. The results indicated that for these species, to obtain the fish pulp it is necessary to include one phase of the procedure, which can be manual or mechanical, because there are no significant differences between them. The formulations selected were: flour corn (10%)--flour soy (30%)--carp (60%), and flour corn (10%)--flour soy (22%)--tilapia (68%). In both cases the condiment mixture was eliminated, and only common salt was used. The protein content was of 40g/100g of the dry product, with a minimum shelflife of 12 weeks at room temperature (22 degrees-23 degrees C). During this period no rancidity developed, the product was microbiologically adequate for human consumption, and proved to have a higher sensory acceptance than sardine patties.     

煤气化飞灰特性的研究进展

在对煤气化飞灰的物理化学性质、微观形貌、气化反应活性和粘附特性归纳分析的基础上,讨论了气化飞灰的形成机理及其气化过程中的结渣倾向性,并对气化过程中避免飞灰在气化炉内的结渣和在合成气冷却器积灰结垢的措施进行了介绍。最后对气化飞灰的研究热点问题进行了展望。     

Development of bakery products for greater adult consumption based on wheat and rice flour

The present investigation was developed as a contribution to Guatemalan's elderly food and nutrition. Its main objective was to evaluate the chemical, nutritional and sensory quality of bread prepared from the partial substitution of wheat flour with rice flour. Wheat flour substitutions with rice flour in the order of 15, 20, 30, 40, 50 and 60% were evaluated. Differences with the control (100% wheat bread) were found during the process of preparation, as well as texture, volume, height, weight and specific volume. Important effects in dough handling were noted specifically in the 40, 50 and 60% rice bread. Thus, a sandy texture was found in breads of higher rice levels. The bread protein quality increased with the level of substitution; however the protein quality difference between the wheat bread and the bread with 60% rice flour did not achieve statistical significance. Based on a statistical analysis of the physical properties the bread with 30 and 40% rice flour was selected, and through a preference test between these last two, the 30% rice flour bread was selected as the sample best suited to the present study's purposes. This bread was not different to wheat bread in many nutritional parameters, although in others it showed to be superior. Each serving size of bread has a weight of 80 grams (2 slices) that contributes adequate quantity of calories, protein and sodium, although a little less dietary fiber than 100% wheat bread.     

Effect of 3 storage temperatures on the quality of kiwi fruit pulp concentrated at a reduced pressure

The effect of three storage temperatures (0, -9 and -18 degrees C) of the kiwi-fruit pulp reduced pressure concentrate, by a period of 3 months, in the physical (soluble solids, water activity, consistency and color), chemistry (pH, acidity, ascorbic acid, chlorophyll and pheophytin) and sensorial (appearance, aroma, acidity, sweetness, color and flavor) characteristics were studied. The greater deterioration was produced in the stored pulp to 0 degree C, while to -9 degrees C there is no significative differences, on the other hand, the kiwi-fruit pulp stored to -18 degrees C maintained large part of the original characteristics. It was observed that while the temperature and storage time increased, vitamin C and chlorophyll contents decreased, varying significantly consistency, color and appearance of product. The rest of the analyzed variables did not present significative differences during storage.     

Mixed drink consisting of guava (Psidium guajava. L) and forrageira palm (Opuntia fícus-indica): development and acceptability

Nowadays, in the beverage industry, the mixture of products became an alternative to increase the nutritional value or even to develop new flavors in the formulation of mixed drinks. The objective of this work was to develop a mixed drink of forrageira palm with guava. Four formulations with different palm concentrations and soluble solids were evaluated, keeping the concentration of guava stable. The products were submitted to chemical characterization (pH, soluble solids, titratable acidity, vitamin C) sensory evaluation (flavor, color, body and global acceptance) and microbiological analysis (total coliforms and thermotolerants, Salmonella and Estaphylococcus aureus). All the samples were well accepted in the sensory aspect and did not present any significant difference (p < 0.5) among them. And the level of acceptance ranged from "I liked it slightly." to "I liked it moderately." for all the evaluated features. The formulated mixed drink was according to the chemical and microbiological patterns set by Brazilian laws, except for the pH that was above the ideal level for industrialized products. In respect of the microbiological analysis, none of the formulations presented microorganisms. The results showed that the elaborated product is in accordance with the identity and quality standards established for beverages. It also has a good sensory acceptance, which makes it a product with high potential for industrialization.     

High-temperature stabilities of low-linolenate,high-stearate and common soybean oils

Four soybean oils (SBO) with different fatty acid (FA) compositions were tested for stability during intermittent heating and frying of bread cubes. None of the oils was hydrogenated or contained any additives. Two of the oils were from common commercial varieties. The other two oils were from seed developed in a mutation breeding program and included the line A5, which contained 3.5% linolenate, and the line A6, which contained 20% stearate. Each oil (450 g) was heated to 185 C in a minifryer. Bread cubes were fried at the beginning of heating, and half were stored at −10 C to preserve freshness. The second half was stored at 60 C for 14 days. Heating was continued for 10 hr/day for four days. After 40 hr of heating, an additional 30 g of bread cubes were fried. According to sensory evaluations of the fried bread cubes, peroxide values of oil extracted from the cubes and conjugated diene values of the oils, the A5 and A6 oils were more stable than those from the commercial varieties. Small differences occurred in the flavor and oxidative stability of the cubes fried after 40 hr of heating the oils. Large differences between A5 and A6 and the commercial varieties occurred after storage of bread cubes for 14 days.     

Fortification of some Egyptian foods with soybean

Flours from full fat and defatted soybeans were made in the laboratory and used as supplements to Egyptian bread and two popular legume foods (lentil soup and falafil). The effect of fortification level on water absorption, dough rheology, loaf quality, and major chemical constituents of fino (pulp) and Arabic (flat) breads were investigated. Water absorption was slightly affected, dough mixing time, stability, and valorimetric values increased, but the mixing tolerance index decreased by adding defatted soy flour to wheat flour. Loaves were slightly smaller in volume than the control at high levels of defatted soy flour. Morover, bread score and panel evaluation showed deterioration of fino bread characteristics above 6% and Arabic bread above 8% defatted soy flour, but above 3% full fat soy. Organoleptic properties of the enriched lentil soup and falafil were similar to those of control at a level of 25% and 50% full fat soy and of 40% and 60% defatted soy flour, respectively. The most favorable change of the chemical composition of lentil soup and falafil is the increased protein content. Also, increasing the level of defatted soy flour increased ash content and decreased the level of fat absorption by fried falafil. On the other hand, increasing the level of full fat soy may replace the addition of shortening to lentil soup to make it more palatable.     

Storage stability of margarines produced from enzymatically interesterified fats compared to those prepared by conventional methods – Chemical properties

In this study, four margarine hardstocks were produced, two from enzymatically interesterified fats at 80 and 100% conversion, one from chemically randomized fat and one from physically mixed fat. These four hardstocks, blended with 50% sunflower oil, were mainly used for the production of table margarines in a pilot plant. Storage stability studies were carried out at storage temperatures of 5 and 25 °C for 12 wk. Margarines from the enzymatically interesterified fats were compared to the margarines produced by the conventional methods (chemical interesterification and physical blending) and to selected commercial margarines. The changes in the chemical properties of the products, including peroxide values (PV), tocopherols, free fatty acids, volatile oxidation products, and sensory evaluation, were examined during storage. It was observed that the margarine produced from the chemically interesterified fat had higher PV in weeks 4, 8 and 10 than the margarines produced from the enzymatically interesterified fats and the physically blended fat. These differences were not caused by different contents of tocopherols in the hardstocks. The differences between the processes for chemical and enzymatic interesterification, including further treatment stages, might be responsible for the development of a high PV in the margarine produced from the chemically interesterified fat. However, the contents of volatiles did not show the same tendency as observed for PV for the margarines stored at 25 °C during 12 wk. Storage at 25 °C accelerated oxidation compared to storage at 5 °C. The content of δ‐ and γ‐tocopherols decreased faster than the content of α‐ and β‐tocopherols during storage. This phenomenon was only affected by storage time, not by storage temperature. Sensory analysis did not show consistent differences between the produced margarines and commercial margarines, and no hydrolysis occurred for these four margarines during storage. The margarines produced from the enzymatically interesterified fats had low PV and a similar taste and smell compared to the margarine produced from the chemically interesterified fat.     

Study of the chemical activation of hydroxyapatite rich ashes as raw materials for geopolymers

The behaviour of ashes, deriving from mixed vegetal and animal biomass incineration, was studied in different alkaline and acidic environments, in order to assess their suitability as primary raw material for low-temperature chemical consolidation. Mixed biomass ashes are mainly based on calcium phosphate and secondly on aluminosilicate compounds; they still represent an unexplored source material to be used in alternative ceramics production. Their chemical behaviour was studied as a function of pH and chemical nature of the leaching solutions, to identify the suitable conditions for ashes chemical consolidation. Preliminary results indicated that acidic digestion of ashes, regardless acid counterion nature, is able to determine the complete decomposition of complex calcium-phosphate phases. Then it allows recombination of dissolved phases into new ones, thus promoting chemical consolidation. Alkaline media were found to be less effective, however, biomass ashes might be successfully regarded as partially reactive fillers for alkali-activated materials.     

Zusammenhang zwischen dem Wasser- und Festfettgehalt und der Austrocknungsgeschwindigkeit beim Auskanten von Margarine

Relationship between Water- und Fat-Content and the Drying-out Rate During Edging of Margarine A mathematical equation has been derived for the correlation between the water and solid fat contents and the drying-out rate of margarine and other plasticised W/O emulsions. A model has been used indicating that under the surface of the product, a completely dried out layer is formed which continuously thickens towards the interior of the product. During this process, the diffusion of the water dissolved in the fat towards the surface, is rate-determining. The experimentally found relations between moisture loss and storage time as well as between moisture loss and water content are in agreement with the formula derived. Using these experimental values, a correction factor has been calculated being dependent on the amount and the particle size of the solid fat phase. With the aid of this factor, the water and solid fat contents and physical constants, the expected moisture loss of plasticised W/O emulsions can be calculated.     

Influence of Drying Temperature on the Physical and Microbiological Parameters and the Quality of Dried Green Onion

The aim of this research was to determine the influence of drying temperature on the physical and microbiological parameters of the green onion and to evaluate the quality and shelf stability of the dried product. To evaluate the stability during storage, measurements of water activity, color parameters, and microbial survival were taken. Drying temperature had little influence on the adsorption isotherms and rehydration rates but had a strong influence on the color parameters and microbial survival. All stability parameters were improved at drying temperature of 70°C. Changes in color limit the shelf life of this product to about 30 days.     

Retention of Ascorbic Acid during Drying of Tomato Halves and Tomato Pulp

The objective of this study was to determine a mathematical model for the reaction kinetics of ascorbic acid degradation to describe the rate of vitamin C loss in a drying process of tomato halves or tomato pulp. Tomato samples with different moisture contents were heated at specified temperatures for different time periods. The kinetics of ascorbic acid degradation followed a first-order reaction with a reaction rate constant dependent on product moisture content, in addition to temperature. Furthermore, there was a maximum rate constant when the moisture content of tomato samples was between 65 and 70%. These effects were expressed by a linear relationship between temperature, moisture content, and natural logarithm of rate constant. The model was used to simulate the vitamin C loss during drying of tomato halves and two drying processes of tomato pulp—evaporative concentration and spray drying. It was concluded that there was a close agreement between the experimental and predicted values of ascorbic acid loss during the tomato pulp concentration, confirming the validity of the proposed model for this process. However, for the spray-drying process and the tomato halves drying a correction coefficient was introduced in the model due to more intense exposure of the product surface to air.     

Bacterial flora of liver paté in 3 stages of processing

Liver paté is a boiled sausage that, due to its nature and composition, has an appropriate environment for bacterial development. In order to determine the variation in the bacterial development during the processing of this sausage, bacteriological examinations were carried out in three stages of preparation. This involved, first, the fresh product, then, after boiling it, and finally on the 6th day, after cold storage at 0 degrees C. Of the bacterial counts obtained it was determined that boiling greatly reduces the number of bacteria, especially the Gram negative ones, a situation which lasts through the storage period studied. The relationship between initial and final bacterial content of liver paté, clearly shows the influence of contamination of the raw materials employed, on the microbiological quality of the marketed product.