The Influence of Different Processing Stages on Particle Size,Microstructure, and Appearance of Dark Chocolate

The effect of different process stages on microstructural and visual properties of dark chocolate was studied. Samples were obtained at each phase of the manufacture process: mixing, prerefining, refining, conching, and tempering. A laser light diffraction technique and environmental scanning electron microscopy (ESEM) were used to study the particle size distribution (PSD) and to analyze modifications in the network structure. Moreover, colorimetric analyses (L*, h°, and C*) were performed on all samples. Each stage influenced in stronger way the microstructural characteristic of products and above all the PSD. Sauter diameter (D [3.2]) decreased from 5.44 μm of mixed chocolate sample to 3.83 μm, of the refined one. ESEM analysis also revealed wide variations in the network structure of samples during the process, with an increase of the aggregation and contact point between particles from mixing to refining stage. Samples obtained from the conching and tempering were characterized by small PS, and a less dense aggregate structure. From color results, samples with the finest particles, having larger specific surface area and the smallest diameter, appeared lighter and more saturated than those with coarse particles.     

Dehydroacetic acid in cheese and cheese coating,results of official control in Italy

This paper reports the occurrence of dehydroacetic acid in cheese and cheese coatings collected in Italy during Agricultural Ministry Official control. Dehydroacetic acid is an antimicrobial substance not allowed to be used in EU countries as a food additive, with unknown effects on human health. Dehydroacetic acid was measured by a validated HPLC method according to Commission Decision 2002/657/EC criteria in terms of specificity, linearity, precision and accuracy, limit of detection, and limit of quantification. The method was successfully applied to 129 samples of commercial cheese coatings and related treated cheeses collected in Italy during 2017. The overall results demonstrated that about 40% of the investigated cheese coatings contained dehydroacetic acid, ranging from 0.010% to 2.5% w/w, evidencing illicit employment of this substance. Moreover, about 25% of treated cheeses contained dehydroacetic acid, from 5 to 250 mg/Kg, proving transfer of this substance from crust to cheese.     

Steering nitrogen fertilisation by means of portable chlorophyll meter reduces nitrogen input and improves quality of fertigated cantaloupe (Cucumis melo L. var. cantalupensis Naud.)

BACKGROUND: Farming is considered one of the main causes of land degradation and underground water pollution. The increased availability of agricultural inputs has led to a dramatic rise in yields, which has resulted in soil fertility spoilage and overuse of fertilisers. Therefore horticultural practice improvement must consider appropriate nitrogen (N) management. This paper reports results on the application of an optical diagnostic system (N‐tester) to guide N fertilisation in muskmelon (Cucumis melo L.) over a 3 year trial. Results on fresh and postharvest quality are also presented. RESULTS: Fertilisation events mirrored increases in N‐tester values during the season, and a significant linear relationship (R² = 0.628) was observed between N‐tester readings and leaf chlorophyll content. The N‐tester‐guided fertilisation treatments were characterised by yields comparable to the control, but with significantly lower applications of N (down to 17–66% of the N distributed in the control). Moreover, the N‐tester treatments yielded fruits with higher sugar content. This was also true after storage, when N‐tester fruits also showed reduced weight loss associated with lower transpiration and ethylene emission rates. CONCLUSION: Through the use of ‘spy plots’ kept at optimal nutritional status and the adoption of a threshold for N application throughout the growing cycle of muskmelon, the N supply was significantly reduced. Therefore a correct application of N‐tester allowed the plant N requirement to be reduced and the fruit sugar content and storability to be increased without adversely affecting the yield. Copyright © 2009 Society of Chemical Industry     

Current Scenario of Adsorbent Materials Used in Ethylene Scavenging Systems to Extend Fruit and Vegetable Postharvest Life

Fruit and vegetables are much appreciated by consumers due to their nutritional values and health-promoting compounds. However, different factors affect the postharvest life of such products, in where ethylene is a major one, even at low concentrations, besides temperature and relative humidity. Therefore, high attention has been focused on the development of effective tools to remove ethylene from the atmosphere surrounding these products during storage or in transit. Potassium permanganate scrubbers are one of the most used technologies to remove ethylene from horticultural products. To facilitate and improve the oxidation process, potassium permanganate has been supported onto inert solid materials of a small particle size. In this review, we aim to provide an outline of the most common materials used as potassium permanganate supports on postharvest treatment and their respective effects on quality aspects of various fresh produce during postharvest life. Vermiculite, activated alumina, zeolite, silica gel, activated carbon and clays are the most popular materials that have been used as a support of potassium permanganate-based ethylene scrubbers. The literature suggests that potassium permanganate supported onto silica gel or zeolite seems to be a promising tool to maintain fruit and vegetables quality attributes for long-term storage. Although vermiculite and activated alumina are the most commonly used materials to reach this goal, not promising results have been reported.     

Rapid point-of-need detection of bacteria and their toxins in food using gold nanoparticles

Biosensors need to meet the rising food industry demand for sensitive, selective, safe, and fast food safety quality control. Disposable colorimetric sensors based on gold nanoparticles (AuNPs) and localized surface plasmon resonance are low-cost and easy-to-perform devices intended for rapid point-of-need measurements. Recent studies demonstrate various facile and versatile AuNPs-based analytical platforms for the detection of bacteria and their toxins in milk, meat, and other foods. In this review, we introduce the general characteristics and mechanisms of AuNPs calorimetric biosensors, and highlight optimizations needed to strengthen and improve the quality of devices for their application in food matrices.     

2012年看标签数字印刷发展及预测汇总

MarcoBoer观任IT Strategies公司副总裁。他是一位高级分析师,同时也是数字印刷行业顾问。在新兴数字印刷市场为财富1000强企业和小型创新公司高管提供成功的商业解决方案,有超过14年的行业经验。从2013年1月起,《数码印刷》特开设Marco专栏,分享他对数码印刷的独到见解。     

Suitability of selected autochthonous lactic acid bacteria cultures for Pecorino Sardo Dolce cheese manufacturing: influence on microbial composition,nutritional value and sensory attributes

The use of an autochthonous starter culture made up by Streptococcus thermophilus, Lactococcus lactis subsp. lactis, Lactobacillus plantarum and Lactobacillus casei in the production of experimental Pecorino Sardo Dolce PDO resulted in a high presence of presumptive mesophilic lactococci and lactobacilli, ~10 log colony‐forming units (cfu), and in significantly higher amount of total free amino acids and free fatty acids, 195.1 vs 178.9 and 328.6 vs 191.8 mg/100 g of experimental vs control cheese (made using a commercial starter) respectively. The experimental cheese also displayed better sensory properties such as taste and aftertaste.