Moisture and Total Solids Analysis

Enhanced biochemical, microbial, and ultrastructural attributes of reduced-fat labneh through innovative microalgae integration

Reduced-fat labneh, while offering health benefits, often presents a challenge due to its diminished nutritional profile compared to full-fat varieties. Microalgae, such as Spirulina platensis and Chlorella vulgaris, are increasingly explored for their potential to fortify foods with essential nutrients. This study innovatively investigates the use of these microalgae to enhance the quality of reduced-fat labneh. The effect of incorporating different concentrations of both microalgae was investigated at different concentrations (0.25, 0.5, and 1%) on nutritional profile (including total solids, fat, protein, carbohydrates, essential amino acids, unsaturated fatty acids, pigments, and phenolic compounds), antioxidant activity, texture, sensory attributes, and viability of the starter culture. The findings revealed that 0.25 and 0.5% concentrations of both microalgae positively influenced the sensory characteristics of the labneh and significantly enhanced its nutritional profile. However, a 1% concentration negatively impacted sensory qualities. Chlorella vulgaris enrichment resulted in higher pH values but compromised texture attributes. Importantly, both microalgae varieties enhanced the viability of the starter culture during 21 days of refrigerated storage. The scanning electron microscope images provide visual evidence of the microstructural changes in labneh with varying concentrations of microalgae and over different storage periods. This research establishes the optimal concentrations for individual microalgae enrichment in reduced-fat labneh, offering valuable insights into their potential to improve both nutritional and sensory aspects. However, it's important to mention that while both microalgae have similar effects, they might differ in their specific impacts due to their unique nutritional profiles and physical properties. Therefore, further investigations could explore optimizing a microalgae mixture and its potential application in functional food development.

Pulsed electric field for shalgam juice: effects on fermentation, shelf-life, and sensory quality

BACKGROUND

Pulsed electric field (PEF) has become a reality in the food industry as a non-thermal application. PEF is used due to its benefits such as increasing the extraction of anthocyanin or other bioactive substances, shortening the fermentation time, and reducing the microbiological load by electroporation. This study aimed to determine the effect of PEF pretreatment on the fermentation, chemical, microbiological, and sensory properties of shalgam juice. For this purpose, PEF with 1 kV cm-1 of field strength was used as a pretreatment for shalgam juice and changes in control and PEF-treated samples were monitored during fermentation and 70 days of cold storage (4 °C).

RESULTS

The pH and lactic acid content during fermentation were similar for both samples. The effect of PEF on pH (3.15-3.39), titratable acidity (4.35-5.49 g L-1 ), total phenolic content (279-766 mg mL-1 GAE) and antioxidant activity (694-2091 μmol Trolox mL-1 ) during storage was insignificant. PEF-treated samples had lower total aerobic mesophilic bacteria (~9%) and lactic acid bacteria (~3%) counts than the control samples at the end of 70 days. Sensory analyses performed at 30th and 60th days of storage with 74 panelists revealed that the color, taste, sourness, saltiness, bitterness, and general acceptability were not inversely affected by PEF.

CONCLUSION

Our results could be a basis to produce shalgam juice commercially by PEF treatment. Although more studies with new experimental designs should be carried out, preliminary results indicated that the use of PEF might have a potential for fermented products such as shalgam juices. © 2023 Society of Chemical Industry.

Evaluation of Heating Times for Loss on Drying at 105°C for Estimation of Laboratory Dry Matter in Animal Feeds

BACKGROUND

Dry matter (DM) is a routine test for all animal feeds, facilitating feed comparisons and diet formulation. It is the most frequent test, yet the most challenging with respect to precision and accuracy.

OBJECTIVE

Our objective was to evaluate the accuracy, repeatability, and physicochemical impacts of oven-drying times on LDM test results in animal feeds obtained by loss on drying (LoD) at 105°C.

METHODS

Eighteen primary samples collected from different feed sources were grouped into high-moisture (HM) and low-moisture (LM) content materials. The tested methods were based on LoD at 105°C and Karl Fischer titration was adopted as the reference method. Test portions were oven dried at 105°C for 3, 6, 12, 16, and 24 h, and test results were compared to the reference method. Test portions were also subjected to a color evaluation using a colorimetric technique.

RESULTS

The method based on 3 h of drying provided the closest estimates to those obtained by Karl Fischer titration. Extending heating time (i.e., above 3 h) increased the bias, especially for HM feeds, which was attributed to a higher occurrence of non-enzymatic reactions. This was corroborated by the color of the residues, which became darker with increased heating time. The repeatability of LoD methods was considered adequate, ranging from 0.32 to 0.73%.

CONCLUSION

The LoD method based on the binomial 105°C × 3 h minimizes the bias in the water recovery and causes less non-enzymatic browning in the test portions.

HIGHLIGHTS

The loss-on-drying method recommended for laboratory DM in animal feeds is drying the test portions at 105°C for 3 h.

A comprehensive review of drying meat products and the associated effects and changes

Preserving fresh food, such as meat, is significant in the effort of combating global food scarcity. Meat drying is a common way of preserving meat with a rich history in many cultures around the globe. In modern days, dried meat has become a well enjoyed food product in the market because of its long shelf-life, taste and health benefits. This review aims to compile information on how the types of meat, ingredients and the used drying technologies influence the characteristics of dried meat in physicochemical, microbial, biochemical and safety features along with technological future prospects in the dried meat industry. The quality of dried meat can be influenced by a variety of factors, including its production conditions and the major biochemical changes that occur throughout the drying process, which are also discussed in this review. Additionally, the sensory attributes of dried meat are also reviewed, whereby the texture of meat and the preference of the market are emphasized. There are other aspects and concerning issues that are suggested for future studies. It is well-known that reducing the water content in meat helps in preventing microbial growth, which in turn prevents the presence of harmful substances in meat. However, drying the meat can change the characteristics of the meat itself, making consumers concerned on whether dried meat is safe to be consumed on a regular basis. It is important to consider the role of microbial enzymes and microbes in the preservation of their flavor when discussing dried meats and dried meat products. The sensory, microbiological, and safety elements of dried meat are also affected by these distinctive changes, which revolve around customer preferences and health concerns, particularly how drying is efficient in eliminating/reducing hazardous bacteria from the fish. Interestingly, some studies have concentrated on increasing the efficiency of dried meat production to produce a safer range of dried meat products with less effort and time. This review compiled important information from all available online research databases. This review may help the food sector in improving the efficiency and safety of meat drying, reducing food waste, while maintaining the quality and nutritional content of dried meat.

Will It Cricket? Product Development and Evaluation of Cricket (Acheta domesticus) Powder Replacement in Sausage, Pasta, and Brownies

Insect powders used in food products may lower the overall quality when compared to conventional counterparts. This preliminary study was used to develop and evaluate insect-based food products and to utilize them in a future consumer test. Pork sausage, dried pasta, and chocolate brownie formulations were developed to either contain NO cricket powder (Control) or have cricket powder (CP). The products were evaluated for proximate composition and product-dependent parameters. The protein content increased in the CP pasta and brownies (p < 0.05) while no changes were found in the sausage (p > 0.05). Fat content increased in both the CP pasta and brownies while it decreased in the CP sausage (p < 0.05). The CP sausage had a higher carbohydrate content than the Control (p < 0.05). Overall, this may be attributed to cricket powder being high in protein and fat while also containing dietary fiber. Cricket powder replacement may lead to noticeable color differences by increasing green and blue coloring in sausage and pasta (p < 0.05). Changes in textural properties (p < 0.05) may be attributed to cricket powder affecting protein solubility and emulsion stability in sausage while gluten formation may be interfered with in the brownies. Overall, cricket powder replacement had improved nutritional content with minor changes in quality parameters.

Multivariate analysis to select chemical compounds and rheological parameters as predictors of bread quality: interaction of wheat genotype and particle size of fine bran

This assay was performed to select chemical compounds and rheological parameters for the prediction of the bread volume and crumb firmness of breads made with a blend of wheat flour-fine bran, using multivariate analysis. Two main factors were used, the source of fine bran and the particle size of fine bran. The experiment consisted in a completely random design, in a 2 × 3 factorial arrangement, the statistical analysis shown that the particle size of fine bran influence almost all the analytical variables. In addition, discriminant analysis was performed to analyse which rheological parameters and chemical components show the greater influence on dough behaviour and bread quality. Biaxial extensional viscosity, farinograph consistency, dough development time and stability were the main rheological parameters that govern the specific volume and crumb firmness and, were both closely related to the fibre, protein and starch content in the flour-fine bran blends. Particle size-genotype interaction has a significant influence on gelatinisation enthalpy and biaxial extensional viscosity that change the bread volume and the crumb firmness. The simplicity of linear equation of five independent variables to predict bread quality with high levels of accuracy could be advantageous in both basic research and the routine quality control of wheat mills.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05290-3.

Amorphization of Thiamine Chloride Hydrochloride: Effects of Physical State and Polymer Type on the Chemical Stability of Thiamine in Solid Dispersions

Thiamine is an essential micronutrient, but delivery of the vitamin in supplements or foods is challenging because it is unstable under heat, alkaline pH, and processing/storage conditions. Although distributed as a crystalline ingredient, thiamine chloride hydrochloride (TClHCl) likely exists in the amorphous state, specifically in supplements. Amorphous solids are generally less chemically stable than their crystalline counterparts, which is an unexplored area related to thiamine delivery. The objective of this study was to document thiamine degradation in the amorphous state. TClHCl:polymer dispersions were prepared by lyophilizing solutions containing TClHCl and amorphous polymers (pectin and PVP (poly[vinylpyrrolidone])). Samples were stored in controlled temperature (30–60 °C) and relative humidity (11%) environments for 8 weeks and monitored periodically by X-ray diffraction (to document physical state) and HPLC (to quantify degradation). Moisture sorption, glass transition temperature (T_g), intermolecular interactions, and pH were also determined. Thiamine was more labile in the amorphous state than the crystalline state and when present in lower proportions in amorphous polymer dispersions, despite increasing T_g values. Thiamine was more stable in pectin dispersions than PVP dispersions, attributed to differences in presence and extent of intermolecular interactions between TClHCl and pectin. The results of this study can be used to control thiamine degradation in food products and supplements to improve thiamine delivery and decrease rate of deficiency.

Relative humidity-temperature transition boundaries for anhydrous β-caffeine and caffeine hydrate crystalline forms

Caffeine is a hydrate-forming polymorphic crystalline compound that can exist in α, β, and hydrate forms. Phase transitions between hydrate and anhydrous forms of a crystalline ingredient, and related water migration, can create product quality challenges. The objective of this study was to determine the relative humidity (RH)-temperature phase boundary between anhydrous β-caffeine and caffeine hydrate. The β-caffeine→caffeine hydrate and caffeine hydrate→β-caffeine RH-temperature transition boundaries were determined from 20 to 45 °C using a combination of water activity (a_w ) controlled solution and vapor-mediated equilibration, moisture sorption, powder X-ray diffraction, and Fourier-transform infrared spectroscopy techniques. Two transition boundaries were measured: the β-caffeine→caffeine hydrate transition boundary (0.835 ± 0.027 a_w at 25 °C) was higher than the caffeine hydrate→β-caffeine transition boundary (0.625 ± 0.003 a_w at 25 °C). Moisture sorption rates for β-caffeine, even at high RHs (>84% RH), were slow. However, caffeine hydrate rapidly dehydrated at low RHs (<30% RH) into a metastable transitional anhydrous state with a similar X-ray diffraction pattern to metastable α-caffeine. Exposing this dehydrated hydrate to higher RHs (>65% RH) at lower temperatures (20 to 30 °C) resulted in full restoration to a 4/5 caffeine hydrate. This transitional anhydrous state was unstable and converted to a less hygroscopic state after annealing at 50 °C and 0% RH for 1 day. It was postulated that the caffeine hydrate→β-caffeine was the true β-caffeine↔caffeine hydrate phase boundary and that β-caffeine could be metastable above the caffeine hydrate→β-caffeine transition boundary. These caffeine RH-temperature transition boundaries could be used for selecting formulation and storage conditions to maintain the desired caffeine crystalline form. PRACTICAL APPLICATION: Caffeine can exist as either an anhydrous (without water) or hydrate (internalized water) crystalline state. The stability of each caffeine crystalline form is dictated by humidity (or water activity) and temperature, and these environmental stability boundaries for the caffeine crystalline forms are reported in this manuscript. Conversions between the two crystalline states can lead to deleterious effects; for example, the presence of caffeine hydrate crystals in a low water activity food (e.g., powder) could lead to the relocation of the water in caffeine to other ingredients in the food system, leading to unwanted water-solid interactions that could cause clumping and/or degradation.

RH-Temperature Stability Diagram of the Dihydrate, β-Anhydrate, and α-Anhydrate Forms of Crystalline Trehalose

Trehalose crystals exhibit polymorphic, deliquescent, and hydrate-forming traits and can exist in dihydrate, β-anhydrate, or α-anhydrate (isomorphic desolvate) forms. The objective of this study was to identify the relative humidity (RH) and temperature boundaries for phase changes of these different trehalose crystal forms. The deliquescence points (RH₀ s) of the anhydrate and dihydrate trehalose crystals were determined from 20 to 50 °C using a combination of water activity and dynamic vapor sorption measurement techniques. Increasing temperatures from 20 to 50 °C resulted in decreases in RH₀ from 95.5% to 90.9% RH for the dihydrate and 69.9% to 62.0% RH for the β-anhydrate. The effects of temperature on the anhydrate-hydrate RH boundaries were also determined, using a combination of equilibration in controlled water activity solutions, powder X-ray diffraction, and Fourier-transform infrared spectroscopy techniques. Increasing temperatures resulted in increases in the anhydrate-hydrate RH boundaries. The irreversible β-anhydrate to dihydrate boundary increased from 44.9% to 57.8% RH, and the reversible α-anhydrate to dihydrate boundary increased from 10% to 25% RH, as temperature increased from 20 to 50 °C. This is the first report of an RH-temperautre stability map for crystalline trehalose. PRACTICAL APPLICATION: The manuscript addresses the issue of the physical stability and phase transformations of crystalline trehalose stored in different temperature and relative humidity environments. Unwanted hydrate formation or dehydration of crystal hydrates can lead to other undesirable water-solid interactions and/or physical modifications that have the potential to influence product quality and delivery traits. Therefore, this study identified relative humidity and temperature stability boundaries of the different trehalose crystal forms, using a variety of established and novel techniques to create a relative humidity-temperature stability map of crystalline trehalose from 20 to 50 °C.

Optimizing the Quality of Food Powder Products: The Challenges of Moisture-Mediated Phase Transformations

Water is ubiquitous in the environment and is present to varying degrees even within dry powder products and most ingredients. Water migration between the environment and a solid, or between different components of a product, may lead to detrimental physical and chemical changes. In efforts to optimize the quality of dry products, as well as the efficiency of production practices, it is crucial to understand the cause-effect relationships of water interactions with different solids. Therefore, this review addresses the basis of moisture migration in dry products, and the modes of water vapor interactions with crystalline and amorphous solids (e.g., adsorption, capillary condensation, deliquescence, crystal hydrate formation, absorption into amorphous solids) and related moisture-induced phase and state changes, and provides examples of how these moisture-induced changes affect the quality of the dry products.