促进柿饼出口的工艺对策

影响柿饼出口的三个限制性因素是交货期晚、卫生指标差和保质期短。本文研究了通过合理的人工干制工艺,使柿饼加工期缩短到50个h左右,卫生指标达到食用卫生标准,保质期在20℃以下长达1年以上。     

Active chitosan–chestnut extract films used for packaging and storage of fresh pasta

A tannins-rich chestnut extract was used to enhance the antioxidant and antibacterial properties of chitosan-based film materials. The favourable mechanical properties of the novel material enabled its application in the preparation of the sachets that were used for packing and storage of filled fresh pasta. The fresh pasta ageing progressed in conventional refrigerated storage conditions of 8 °C with 60 ± 2% relative humidity in the absence of light for 60 days. The rapid moisture mobility between a starchy food and sachets during the first 9 days of storage induced retrogradation of the fresh pasta, whereby total phenolic content show dependency on moisture throughout the shelf life. Active components within the sachet prevented microbial growth on the food surface during the entire 60 days.     

Berry fruits-enriched pasta: effect of processing and in vitro digestion on phenolics and its antioxidant activity,bioaccessibility and potential bioavailability

Pasta samples were made by substituting wheat flour (2.5% and 7.5%) for lyophilised raspberry, boysenberry, and redcurrant and blackcurrant. Total polyphenol content showed minimum variation during processing while anthocyanins presented high degradation. In general, the first minutes of cooking showed the major detrimental effect on antioxidant activity. In vitro starch hydrolysis showed the lowest value with the addition of raspberries and boysenberries. During simulated digestion, polyphenols were released from pasta matrix reaching a 2.3- to 4.3-fold increase in bioaccessible polyphenols. Likewise, values observed for reducing power and free radical scavenging activity ranged from a 0.7- to 2.0-fold and 1.6- to 6.8-fold increase in relation to cooked pasta, respectively. In addition, ≈40% of dialysability was observed for scavenging activity. In conclusion, enrichment of pasta with fine fruits is an effective tool to obtain a product with enhanced antioxidant potential.     

Nutritional quality variation in dried Pacific Oyster (Crassostrea gigas) using hybrid-pump dryer under different heating treatment

Food Science and Biotechnology - This study explored the potential of using hybrid pump dryer (HPD) to utilize overproduction in aquaculture of oysters, especially during winter. HPD-dried oysters...     

Effect of chemical and physical properties of Dried Distillers Grains with solubles (DDGS) on Tribolium castaneum (Herbst) development

Dried Distillers Grains with Solubles (DDGS) has been used as a grain-based supplement in animal feed. The focus of this study was to investigate the effects of chemical and physical characteristics that may affect DDGS susceptibility to Tribolium castaneum (Herbst) infestation. Multiple regression-based models were built to determine if the diet’s chemical and physical characteristics affect T. castaneum development. Based on the regression models, diet particle size was the most influential factor in larval development. Larval weight increased more rapidly on T. castaneum normal laboratory diet, 90% flour/10% brewer’s yeast (F/Y), followed by ground DDGS, compared to raw DDGS with different particle sizes. To determine the effect of diet particle size on larval development, experiments were conducted to increase particle size by pelletizing F/Y using a rotary drum granulation apparatus. T. castaneum larval stage lasted significantly longer on F/Y granules with a particle size of 1.4 mm or larger. Although the chemical properties of DDGS (protein, fat, fiber and ash content) were not significant predictors of T. castaneum larval development, larval developmental time and weight gain on ground DDGS was significantly slower than on F/Y, highlighting the potential importance of nutritional factors not accounted for in our analysis. Our results conclude that storing DDGS as raw ingredient and in the granule or pellet form with large particle size may help limit T. castaneum infestations. Although granulation or pelletization may not be economically feasible for small manufacturing plants, larger producers may benefit from the reduced risk of insect contamination associated with secondary feeders such as T. castaneum.     

Characterization of hyperporous polyurethane-based gels by non-intrusive mercury porosimetry

Evaporative drying of polyurethane-based gels produces xerogels. Supercritical drying after replacement of interstitial liquid by supercritical CO₂ produces aerogels. SEM micrographs show that both materials are made up of small size particles gathered up in filament-shaped, strongly cross-linked aggregates. Density measurements show that they both have a large pore volume.When submitted to mercury porosimetry, the behavior of these materials is similar to that of inorganic aerogels, as previously observed. Mercury does not penetrate the pore network, but the whole material is densified. The usual Washburn equation cannot be used to analyze the mercury porosimetry. A well-suited equation based on a buckling model of filament-shaped aggregates has been developed in order to determine the pore volume distribution of mineral dried gels. This equation is also valid for analyzing the texture of organic hyperporous materials like polyurethane dried nanoporous gel.     

Retention of the Enzymatic Activity and Product Properties During Spray Drying of Pineapple Stem Extract in Presence of Maltodextrin

The aim of this work was to investigate the effects of drying parameters on the retention of the enzymatic activity and on the physical properties of spray-dried pineapple stem extract. A Box and Behnken experimental design was used to investigate the effects of the processing parameters on the product properties. The parameters studied were the inlet temperature of drying gas (Tgi), the feed flow rate of the pineapple extract relative to evaporative capacity of the system (W_s?/W_max), and the concentration of maltodextrin added to the extract (MD). Significant effects of the processing parameters on the retention of the proteolytic activity of the powdered extract were observed. High processing temperatures lead to a product with a smaller moisture content, particle size, and lower agglomerating tendency. A product with insignificant losses of the proteolytic activity (≈ 10%) and low moisture content (less than 6.5%) is obtained at selected conditions.     

Time and speed of fruit drying on batch fluid-beds

Drying of particles (pieces) in a fluidized bed affords better quality of end products, especially for better product structure and its shorter reconstitution time. Fluid-bed drying of different fruit particles has been investigated. Starting water content varies from grape berries 81.5% and peach 87.7% to apricot 86.9%. The temperature of fluidization varies from 70°C to 100°C at air velocities from 0.98 ms⁻¹ to 5.2 ms⁻¹. The product should be dried fruit with 10% to 14% of water content with good rehydration quality that varies from 8 to 20. Experimental data have been measured, relevant values have been calculated and a mathematical model introduced. The results have shown that drying of fruit in a fluidized bed produces dry fruit particles of improved quality in a much shorter time, with improved rehydration times and qualities, than in continuous belt-driers that are generally used.