Second Cheese Whey Treatment Using Zeolite under Continuous Flow Mode and Its Application on Wheat Growth

Evaluation of Cellular Responses by Chlamydomonas reinhardtii in Media Containing Dairy-Processing Residues Derived from Cheese as Nutrients by Analyzing Cell Growth Activity and Comprehensive Gene Transcription Levels

Utilities of whey powder (WP) and whey protein concentrate 34% powder (WPC34) prepared as dairy-processing residues were evaluated using a green alga Chlamydomonas reinhardtii. Analysis of C. reinhardtii growth showed that the strain used WP and WPC34 as nitrogen sources. Its specific growth rate and maximum cell density in WP-containing medium were higher than those in WPC34-containing medium; growth with WPC34 was improved by adding KCl or K2HPO4, which content was decreased as a result of WPC34's preparation from WP. Although the lipid contents in media containing dairy-processing residues were 2.72 ± 0.31 wt% and 2.62 ± 0.20 wt% with no significant difference, the composition ratio of fatty acid C14 with WPC34 was higher than that with WP and the composition ratio of the sum of fatty acid-C16 and -C18 with WPC34 tended to be lower than that with WP. Additionally, analyses of gene transcription showed that the transcription level of acetyl-CoA carboxylase biotin carboxyl carrier protein in WPC34-containing medium was lower than that in WP-containing medium, possibly affecting the ratios of the chain lengths of fatty acids. The transcription of genes involved in glycolysis and the TCA cycle was outstandingly lower in algae grown in WPC34-containing medium when compared to those cultivated in the presence of WP, resulting in differences in energy production for cell proliferation.

Graduate Student Literature Review: History, technologies of production, and characteristics of ricotta cheese

This review focused on the historical, technological, and analytical characteristics of ricotta cheese available in the literature. Ricotta cheese is a typical dairy product that originated from Italy, used in the preparation of several traditional dishes, both sweet and salted. The available studies pertaining to ricotta cheese revealed a considerable biodiversity in the production with a large number of varieties produced, whose production varies according to the local uses and customs. The review shows the main chemical and microbial characteristics of the product and also the several parameters that affect the mechanism of the production process and the final characteristics of the product, including the raw materials, the processing methods, the season, the animals' diet, the animals' species, and breeds. Ricotta production can be artisanal or industrial, with differences in the making process. New trends in ricotta cheese production have been developed, with particular attention to the functional effect on human health and the novel technologies applied to extend the shelf-life of the products. Currently, it is not easy to find these new developments in the market, probably related to the cost of production, which is not always bearable by the farms. However, despite the large classification reported and the great interest by the cheese industry, just a few numbers of studies were found for artisanal ricotta productions, which still need to be characterized and studied.

Thermally Modified Palygorskite Usage as Adsorbent in Fixed-Bed Reactor for High Concentration NH4+-N Removal and Further Application as N-Fertilizer in Hydroponic Cultivation

Palygorskite sample (Pal) underwent thermal treatment at 400 °C (T-Pal) to be used as adsorbent for the removal of 200 mg NH₄⁺-N/L from artificial solution. After thermal treatment, the sample was characterized via X-ray diffraction (XRD) and scanning electron microscopy (SEM). For NH₄⁺-N removal, T-Pal was added as a bed matrix in fixed-bed reactor experiments and the effect of flow rate was determined. It was indicated that with the flow rate increase from 10 mL/min to 50 mL/min, fewer liters of the solution were purified, rendering a longer residual time of interactions, which is optimal for NH₄⁺-N removal from T-Pal. The maximum removed amount was calculated at 978 mg NH₄⁺-N (q_total), suggesting T-Pal is a promising ammonium adsorbent. The data of kinetic experiments were applied to Clark, Yoon-Nelson, and Thomas kinetic models, with Clark having the best fit, highlighting a heterogenous adsorption. At the end of kinetic experiments, T-Pal applied in hydroponic cultivations and presented a sufficient release rate, which was found utilizable for saturated T-Pal usage as N fertilizer that satisfactory results were deemed concerning lettuces characteristics and growth.

Development and Characterization of a Novel Sustainable Probiotic Goat Whey Cheese Containing Second Cheese Whey Powder and Stabilized with Thyme Essential Oil and Sodium Citrate

Probiotic goat whey cheeses with added second cheese whey powder (SCWP) were developed, resulting in creamy and spreadable products. The products contained Lactobacillus rhamnosus and Bifidobacterium animalis, as well as thyme essential oil and sodium citrate. Matrices of probiotic whey cheeses, with and without additives, were produced and stored at 5 °C for 21 days. Microbial and chemical profiles were evaluated weekly. The composition of the optimum matrix, formulated with whey cheese, probiotic culture, SCWP, thyme essential oil and sodium citrate (WCPSTC) was, expressed in % (w/w): protein (10.78 ± 0.08), fat (7.59 ± 0.03), dry matter (25.64 ± 0.13), ash (2.81 ± 0.02) and lactose (3.16 ± 0.04). Viable cell numbers of both probiotic cultures in matrix WCPSTC remained above 10⁷ CFU g⁻¹. This finding is of the utmost importance since it proves that both probiotic bacteria, citrate and thyme essential oil can be combined in order to increase the shelf-life and functional value of dairy products. All matrices’ pH values decreased during storage, yet only matrix WCPSTC remained above 5.0 pH units. The results indicated that the development of a probiotic whey cheese incorporating a dairy by-product, SCWP, is possible without compromising its chemical, microbiological or sensorial stability.

Dairy By-Products: A Review on the Valorization of Whey and Second Cheese Whey

The search for new food products that promote consumers health has always been of great interest. The dairy industry is perhaps the best example regarding the emergence of new products with claimed health benefits. Cheese whey (CW), the by-product resulting from cheese production, and second cheese whey (SCW), which is the by-product of whey cheese manufacture, have proven to contain potential ingredients for the development of food products with improved nutritional characteristics and other functionalities. Nowadays, due to their nutritional quality, whey products have gained a prominent position among healthy food products. However, for a long time, CW and SCW were usually treated as waste or as animal feed. Due to their high organic content, these by-products can cause serious environmental problems if discarded without appropriate treatment. Small and medium size dairy companies do not have the equipment and structure to process whey and second cheese whey. In these cases, generally, they are used for animal feed or discarded without an appropriate treatment, being the cause of several constraints. There are several studies regarding CW valorization and there is a wide range of whey products in the market. However, in the case of SCW, there remains a lack of studies regarding its nutritional and functional properties, as well as ways to reuse this by-product in order to create economic value and reduce environmental impacts associated to its disposal.

Agro-Industrial Wastewater Treatment with Decentralized Biological Treatment Methods

Food processing consumes high volumes of water, making agro-industries the third biggest industrial user of water after oil refineries, primary metals and chemicals industries [...]

Simultaneous removal of ammonium nitrogen, dissolved chemical oxygen demand and color from sanitary landfill leachate using natural zeolite

In this study, natural zeolite with maximum adsorption capacity of 3.59 mg g^-1 was used for the simultaneous removal of ammonium nitrogen (NH₄⁺-N), dissolved chemical oxygen demand (d-COD) and color from raw sanitary landfill leachate (SLL). Saturation, desorption and regeneration tests of zeolite were performed. Optimum adsorption conditions were found for particle size 0.930 µm, stirring rate of 1.18 m s^-1, zeolite dosage of 133 g L^-1 and pH 8. NH₄⁺-N removal efficiency reached 51.63 ± 0.80% within 2.5 min of contact. NH₄⁺-N adsorption follows mostly the linear pseudo-second order model, with intra-particle diffusion. NH₄⁺-N desorption follows the linear pseudo-second order model. Adsorption data fitted to the Temkin Isotherm in linear and nonlinear forms. Saturation tests showed that zeolite can be efficiently used in three successive adsorption cycles. NH₄⁺-N release from the saturated zeolite was not completely reversible, suggesting that the zeolite may be used as slow ΝΗ₄⁺-Ν releasing fertilizer and an attractive low cost material for the treatment of SLL. NH₄⁺-N removal with the regenerated zeolite exceeded 40% of the initial concentration in the fluid within 2.5 min. SEM analysis showed significant changes through saturation and regeneration. XPS revealed that adsorption of ΝΗ₄⁺-Ν to the zeolite was accompanied by ion exchange.