Effect of shearing-induced lipolysis on foaming properties of milk

BACKGROUND The attraction of cappuccino-style beverages is attributed to the foam layer, as it greatly improves the texture, appearance, and taste of these products. Typical milk has a low concentration of free fatty acids (FFA), but their concentration can increase due to lipolysis during processing and storage, which is detrimental to the foamability and foam stability of milk. There are contradictory results in reported studies concerning the effects of FFA on the foaming properties of milk due to differences in milk sources, methods inducing lipolysis, and methods of creating foam. In this study, the foaming properties and foam structure of milk samples whose lipolysis was induced by ultra-turraxing, homogenisation, and microfluidisation (1.5–3.5 μ-equiv.mL−1 FFA) were investigated. RESULTS Compared with others, microfluidised milk samples had the smallest particle size, lowest absolute zeta potential, and highest surface tension; thus exhibited high foamability and foam stability, and very small and homogeneous air bubbles in foam structure. For all shearing methods, increasing FFA content from 1.5 to 3.5 μ-equiv.mL−1 markedly decreased the surface tension, foamability, and foam stability of milk samples. The FFA level that led to undesirable foam structure was 1.5 μ-equiv.mL−1 for ultra-turraxed milk samples and 2.5 μ-equiv.mL−1 for homogenised and microfluidised ones. CONCLUSION Shearing-induced lipolysis greatly affected the physical properties of milk samples and subsequently their foaming properties and foam structure. At the same FFA level, lipolysis induced by microfluidisation was much less detrimental to the foaming properties of milk than lipolysis induced by ultra-turraxing and homogenisation.Peer reviewe

Acid gelation properties of camel milk—effect of gelatin and processing conditions

This study investigated the effects of glucono-delta-lactone (GDL) concentrations (0.8-1.2%, w/w), gelatin content (0.6-1.0%, w/w) and processing conditions on the properties of camel milk acid gels. Although the pH of camel milk reduced to 4.3 within 4 h of acidification at 1.0% GDL, it was unable to form a suitable gel for a yoghurt-like product unless gelatin was added. At 0.8% gelatin, camel milk gels had similar hardness, lower viscosity and rheological strength, and higher water holding capacity as compared to cow milk gels. Heating of camel milk (85 degrees C/15-20 min), 2-stage homogenization (150/50 bar) or their combination did not significantly affect the water holding capacity, hardness, viscosity, rheological strength and microstructure of camel milk gels. These processing conditions did not affect protein integrity as confirmed by sodium dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis.Peer reviewe

Ultraaccurate genome sequencing and haplotyping of single human cells.

Accurate detection of variants and long-range haplotypes in genomes of single human cells remains very challenging. Common approaches require extensive in vitro amplification of genomes of individual cells using DNA polymerases and high-throughput short-read DNA sequencing. These approaches have two notable drawbacks. First, polymerase replication errors could generate tens of thousands of false-positive calls per genome. Second, relatively short sequence reads contain little to no haplotype information. Here we report a method, which is dubbed SISSOR (single-stranded sequencing using microfluidic reactors), for accurate single-cell genome sequencing and haplotyping. A microfluidic processor is used to separate the Watson and Crick strands of the double-stranded chromosomal DNA in a single cell and to randomly partition megabase-size DNA strands into multiple nanoliter compartments for amplification and construction of barcoded libraries for sequencing. The separation and partitioning of large single-stranded DNA fragments of the homologous chromosome pairs allows for the independent sequencing of each of the complementary and homologous strands. This enables the assembly of long haplotypes and reduction of sequence errors by using the redundant sequence information and haplotype-based error removal. We demonstrated the ability to sequence single-cell genomes with error rates as low as 10-8 and average 500-kb-long DNA fragments that can be assembled into haplotype contigs with N50 greater than 7 Mb. The performance could be further improved with more uniform amplification and more accurate sequence alignment. The ability to obtain accurate genome sequences and haplotype information from single cells will enable applications of genome sequencing for diverse clinical needs

Addressing Health Disparities in Middle School Students’ Nutrition and Exercise

Those with low income, especially women of African American and Hispanic heritage have the greatest risk of inactivity and obesity. A 4-session (Internet and video) intervention with healthy snack and gym labs was tested in 2 (gym lab in 1) urban low–middle-income middle schools to improve low fat diet and moderate and vigorous physical activity.1 The gym lab was particularly beneficial (p = .002). Fat in diet decreased with each Internet session in which students participated. Percentage of fat in food was reduced significantly p = .018 for Black, White, and Black/Native American girls in the intervention group. Interventions delivered through Internet and video may enable reduction of health disparities in students by encouraging those most at risk to consume 30% or less calories from fat and to engage in moderate and vigorous physical activity

Properties of functional camel milk powder

Camel milk has a composition and properties quite close to human milk. Camel milk’s composition is considered superior to that of bovine milk in terms of its nutritional and therapeutic value. It contains high concentrations of several bioactive compounds that have health benefits. To achieve long-term stability and usability, many dairy-based products and ingredients are dehydrated to powder form. However, such severe heat treatments eventuate in the loss of heat-labile bioactive compounds. Protecting these bioactive compounds during the production of camel milk powder is a challenge for dairy researchers and manufactures. To maintain the activity of such compounds, low-temperature drying operations such as freeze-drying are preferred, and there are many freeze-dried camel milk powder products available on the market. However, due to the limitations of freeze-drying in the production of milk powder, freeze-drying needs to be replaced with other economic drying approaches such as spray drying. However, the application of spray drying in the production of camel milk powder is still in early stages of research, and there are only a few reported studies. This chapter describes the bioactive properties of camel milk and the potential application of spray drying to produce camel milk powder.Peer reviewe

Effect of pH and heat treatment on physicochemical and functional properties of spray-dried whey protein concentrate powder

Effects of pH and heating on deamidation of whey protein concentrate (WPC) solution and functional properties of resultant spray-dried WPC powder were investigated. Temperature and heating time affected deamidation rates with the highest reactivities for WPC solutions heated at 120 °C for 15 min and 145 °C for 120 s. Deamidation sites were pH dependent: pH 3 induced more glutamine deamidation; pH 10 induced more asparagine deamidation. The functional properties of spray-dried WPC powders were also pH dependent. WPC solution adjusted to pH 3 and heated at 145 °C for 120 s (prior to spray drying) exhibited a reduction in solubility and foamability, but markedly improved foam stability of the resultant powders; meanwhile, the properties of powders were not significantly impacted by pH adjustment to 10.0 and heating at 145 °C for 120 s. However, pH 3 and 10 with and without heating significantly improved emulsifying properties of spray-dried WPC.Peer reviewe

Changes in surface chemical composition relating to rehydration properties of spray-dried camel milk powder during accelerated storage

Alterations in surface chemical composition relating to rehydration properties of spray-dried camel milk powders during accelerated storage (11–33% RH, 37 °C) over 18 weeks were investigated. The results showed that the surface of the fresh spray-dried camel milk powder (t = 0) was dominated by lipids (78%), followed by proteins (16%) and lactose (6%). During storage, the surface protein and lactose content decreased while the surface lipid content increased, resulting in an increase in surface hydrophobicity and slight agglomeration of the powder, especially for powder kept at 33% RH. Although fresh camel milk powder had very poor wettability, it displayed very high dispersibility and solubility (99%). During storage, dispersibility and solubility declined with increasing storage time and increasing RH levels, which correlated with an increase in surface lipid content. However, at the end of the storage period, camel milk powder still retained very high solubility (>93%).Peer reviewe

Evaluating Very Long-Term Conversational Memory of LLM Agents

Existing works on long-term open-domain dialogues focus on evaluating model responses within contexts spanning no more than five chat sessions. Despite advancements in long-context large language models (LLMs) and retrieval augmented generation (RAG) techniques, their efficacy in very long-term dialogues remains unexplored. To address this research gap, we introduce a machine-human pipeline to generate high-quality, very long-term dialogues by leveraging LLM-based agent architectures and grounding their dialogues on personas and temporal event graphs. Moreover, we equip each agent with the capability of sharing and reacting to images. The generated conversations are verified and edited by human annotators for long-range consistency and grounding to the event graphs. Using this pipeline, we collect LoCoMo, a dataset of very long-term conversations, each encompassing 300 turns and 9K tokens on avg., over up to 35 sessions. Based on LoCoMo, we present a comprehensive evaluation benchmark to measure long-term memory in models, encompassing question answering, event summarization, and multi-modal dialogue generation tasks. Our experimental results indicate that LLMs exhibit challenges in understanding lengthy conversations and comprehending long-range temporal and causal dynamics within dialogues. Employing strategies like long-context LLMs or RAG can offer improvements but these models still substantially lag behind human performance.Comment: 19 pages; Project page: https://snap-research.github.io/locomo

A genetic diversity study of antifungal Lactobacillus plantarum isolates

Lactobacillus plantarum is a lactic acid bacterium commonly found on fruits and vegetables and also used in a variety of food fermentations. Strains from this species are also regularly reported as having antifungal or probiotic activity. Genotyping methods can be used to differentiate strains of the same species thus determining if strains are related or not. However for L.\ua0plantarum, the currently used methods have limitations including DNA band profile interpretation difficulty and cost. In this study, a new genotyping method based on multi-locus variable number tandem repeat analysis (MLVA) was developed and compared to a previously reported randomly amplified polymorphic DNA-PCR (RAPD-PCR) method for L.\ua0plantarum. With a selection of 13 antifungal strains of L.\ua0plantarum isolated from heterogeneous sources (cheese, silage, sauerkraut, vegetables and a probiotic product), RAPD-PCR revealed 9 different profiles resulting in a Hunter-Gaston discrimination index (D-value) of 0.94. The new MLVA method which compares the lengths of 4 repetitive regions within LPXTG motif-containing surface protein genes differentiated the 13\ua0L.\ua0plantarum strains into 10 different subtypes leading to a D-value of 0.95. Interestingly 11 additional L.\ua0plantarum isolates obtained in a previous study during a screen for antifungal activity against the common cheese spoilage mould Penicillium commune all possessed the same RAPD-PCR and MLVA profile as each other and the commercial probiotic strain L.\ua0plantarum 299v. This study demonstrates that the new MLVA method can be used to simply and inexpensively differentiate L.\ua0plantarum strains and provide information regarding strain relatedness and thus potential insight into strain properties

The muscle protein dysferlin accumulates in the Alzheimer brain

Dysferlin is a transmembrane protein that is highly expressed in muscle. Dysferlin mutations cause limb-girdle dystrophy type 2B, Miyoshi myopathy and distal anterior compartment myopathy. Dysferlin has also been described in neural tissue. We studied dysferlin distribution in the brains of patients with Alzheimer disease (AD) and controls. Twelve brains, staged using the Clinical Dementia Rating were examined: 9 AD cases (mean age: 85.9 years and mean disease duration: 8.9 years), and 3 age-matched controls (mean age: 87.5 years). Dysferlin is a cytoplasmic protein in the pyramidal neurons of normal and AD brains. In addition, there were dysferlin-positive dystrophic neurites within Aβ plaques in the AD brain, distinct from tau-positive neurites. Western blots of total brain protein (RIPA) and sequential extraction buffers (high salt, high salt/Triton X-100, SDS and formic acid) of increasing protein extraction strength were performed to examine solubility state. In RIPA fractions, dysferlin was seen as 230–272 kDa bands in normal and AD brains. In serial extractions, there was a shift of dysferlin from soluble phase in high salt/Triton X-100 to the more insoluble SDS fraction in AD. Dysferlin is a new protein described in the AD brain that accumulates in association with neuritic plaques. In muscle, dysferlin plays a role in the repair of muscle membrane damage. The accumulation of dysferlin in the AD brain may be related to the inability of neurons to repair damage due to Aβ deposits accumulating in the AD brain