Early Production Phase Research Articles

EVALUATION OF GROWTH PERFORMANCE AND SURVIVABILITY OF TWO STRAINS OF LAYER CHICKEN AT STARTER PHASE OF PRODUCTION

The Nigeria poultry industry has over the years witnessed the introduction of different strains of layer chicken. The growth and productivity of these strains largely depend on the nutritional and climatic variables as well as genetic make-up of these strains. This implies that chicken producers should consider strains with high genetic potential for better production under their climatic conditions. Therefore, a study was conducted to evaluate growth performance and survivability of two strains of layer chicken at starter phase of production. A total of 120 birds (60 each of Isa brown and Nera black) were used. The birds were divided into two treatment groups according to strain and each group was randomly replicated four times with 15 birds per replicate and was raised for eight weeks in deep litter system. Parameters measured were body weight, daily weight gain, total weight gain, daily feed intake, total feed intake and feed conversion ratio. Data were subjected to Independent T-test of SPSS. Nera Black had the most superior body weight, weight gain and feed conversion ratio (1271.04 ± 15.30g, 1236.54 ± 6.57 and 2.44 ± 0.06) respectively. The result also indicated that strain had significant (p<0.05) influence on survivability, with Nera Black (91.1%) being superior to Isa Brown (88.80%) strains. Based on the results of this study, it was concluded that Nera black layers had better growth performance and survivability than the Isa Brown layers at starter phase. It was therefore, recommended that Nera black should be used since it offers a better growth performance at the early phase of production which may eventually leads to better lay during the laying phase.

Internal Organ Colonization by Salmonella Enteritidis in Layer Pullets Infected at Two Different Ages During Rearing in Cage-Free Housing.

The poultry-housing environment plays a significant role in the transmission and persistence of the egg-associated pathogen Salmonella Enteritidis in laying flocks. The commercial egg industry is in the midst of a transition toward cage-free housing, but the food safety ramifications of this shift are not yet certain. The present study assessed internal organ colonization by Salmonella Enteritidis in layer pullets reared in cage-free housing and infected at two different ages. Groups of 280 pullets were transferred from the rearing facility (at 9 wk of age in one trial and 15 wk in another) to a containment facility with four isolation rooms simulating commercial cage-free barns with perches and nest boxes (70 birds/room). Twenty-four pullets in each room were orally inoculated with Salmonella Enteritidis immediately after placement in the containment facility. At 1-2 wk postinoculation in each trial, samples of liver, spleen, and intestinal tract were collected from all birds in two rooms for bacteriologic culturing to detect Salmonella Enteritidis. At 21-22 wk of age, samples of spleen, ovary, and intestinal tract were similarly collected and tested from all birds in the remaining two rooms. Among samples collected at 1-2 wk postinoculation, Salmonella Enteritidis was isolated significantly more often from groups of pullets infected initially at 15 wk of age than from those infected at 9 wk (61% vs. 38% of livers, 59% vs. 31% of spleens, and 84% vs. 57% of intestines). Among samples collected at 21-22 wk of age, the frequency of recovery of Salmonella Enteritidis was again significantly greater in birds infected at 15 wk of age than in those infected at 9 wk (16% vs. 6% of spleens, 9% vs. 1% of ovaries, and 26% vs. 10% of intestines). These data suggest that Salmonella Enteritidis infections introduced into flocks during the later stages of pullet rearing have greater potential to persist into the early phase of egg production.

Environmental considerations along the life cycle of pharmaceuticals: Interview study on views regarding environmental challenges, concerns, strategies, and prospects within the pharmaceutical industry

Environmental impacts of medicines arise throughout their entire life cycle. The pharmaceutical industry has a key role in reducing these impacts in early production phases, but currently has limited possibilities to reduce the environmental exposure arising from drug consumption and end-of-life. The aim of this interview study was to explore the current environmental actions within the industry, as well as the views and attitudes toward the strategies to address the environmental challenges and concerns. Semi-structured interviews were conducted among representatives (n = 15) from twelve pharmaceutical companies operating in Finland in February-May 2021. The data were analyzed using qualitative content analysis.The representatives of pharmaceutical industry were overall well aware of the multifaceted environmental challenges related to the life cycle of pharmaceuticals and of their role in improving sustainability in production. Improving waste management and reducing impacts from companies’ own operations were the most commonly mentioned actions already taking place within the companies (15/15). “Environmental impacts arising from drug consumption” (6/15) and “centralized drug manufacturing in countries with lax environmental regulation” (4/15) were most frequently brought up challenges difficult to resolve. “Development of environmentally more sustainable drug production in the company” was the most frequently raised key development need (5/15). To address this, establishment of tangible economic drivers, regulatory incentives, or reputational rewards were called for. “Incorporation of environmental aspects into decision-making in different situations” was suggested by 11/15 interviewees as a means to promote sustainable development, e.g. in selection of medicines by physicians and consumers. However, the attitudes towards the types of criteria and their evaluation differed between interviewees. Attitudes towards the “incorporation of environmental fate assessment into early phases of drug design and development” were mostly positive (10/11), suggesting that there is a keen interest in the industry to foster the introduction of new tools enabling the development of pharmaceuticals intrinsically less harmful for the environment.

Dietary Supplementation of Tannins: Effect on Growth Performance, Serum Antioxidant Capacity, and Immunoglobins of Weaned Piglets-A Systematic Review with Meta-Analysis.

In recent years, the swine industry has witnessed the withdrawal of antibiotics and continuous regulation of zinc and copper oxides in the early-life nutrition of piglets. Due to this development, alternative additives from plant sources have been extensively explored. Therefore, this study's objective was to evaluate the effect of dietary supplementation with tannins on weaned piglets' growth performance, serum antioxidant capacity, and serum immune status using a systematic review and meta-analysis approach. A total of 16 studies with parameters of interest were deemed eligible after a two-step screening process following a comprehensive literature search in the scientific databases of Web of Science, Scopus, ScienceDirect, PubMed, and Google Scholar. The inclusion criteria were mainly (1) studies involving basal diet supplemented with tannins and (2) studies with the quantification of tannin doses, while the exclusion criteria were (1) studies with pre- and post-weaning pigs and (2) challenged studies. Applying the random-effects models, Hedges' g effect size of supplementation with tannins was calculated using R software to determine the standardized mean difference (SMD) at a 95% confidence interval. Sub-group analysis and meta-regression further explored heterogeneity (PSMD < 0.05, I2 > 50%, n ≥ 10). Supplementation with tannins reduced the feed conversion ratio (p < 0.01) but increased the final body weight (p < 0.01) of weaned piglets. Chestnut and grape seed proanthocyanidin tannin sources yielded higher effects on growth performance. In addition, meta-regression models indicated that tannin dosage and supplementation duration were directly associated with tannins' effectiveness on productive performance. In the serum, the concentration of glutathione peroxidase, superoxide dismutase, and total antioxidant capacity were elevated (p < 0.01) in response to tannin supplementation, whereas malondialdehydes was reduced (p < 0.01). Likewise, increased immunoglobin M and G levels (p < 0.01) were detected. In conclusion, dietary supplementation with tannins, particularly with chestnut and grape seed proanthocyanidins, increases the productivity of weaned piglets. At the same time, it is a possible nutritional strategy to mitigate oxidative stress and stimulate gut health. Thus, supplementing chestnut and grape seed proanthocyanidin tannins in the early phase of swine production could be used to alleviate the incidence of diarrhea.

Analysis of global research on vegetable seedlings and transplants and their impacts on product quality.

Previous research has established that using high-quality planting material during the early phase of vegetable production significantly impacts success and efficiency, leading to improved crop performance, faster time to harvest and better profitability. In the present study, we conducted a global analysis of vegetable seedlings and transplants, providing a comprehensive overview of research trends in seedling and transplant production to enhance the nutritional quality of vegetables. The analysis involved reviewing and quantitatively analysing 762 articles and 5248 keywords from the Scopus database from 1971 to 2022. We used statistical, mathematical and clustering tools to analyse bibliometrics and visualise the most relevant research topics. A visualisation map was generated to identify the evolution of keywords used in the articles, resulting in five clusters for further analysis. Our study highlights the importance of the size of seed trays for the type of crop, the mechanical seeder used and the greenhouse facilities to produce desirable transplants. We identified grafting and light-emitting diode (LED) lighting technology as rapidly expanding technologies in vegetable seedlings and transplant production used to promote plant qualitative profile. There is a need for sustainable growing media to optimise resources and reduce input use. Thus, applying grafting, LED artificial lighting, biostimulants, biofortification and plant growth-promoting microorganisms in seedling production can enhance efficiency and promote sustainable vegetable nutritional quality by accumulating biocompounds. Further research is needed to explore the working mechanisms and devise novel strategies to enhance the product quality of vegetables, commencing from the early stages of food production. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Surface Defect Mitigation of Additively Manufactured Parts Using Surfactant-Mediated Electroless Nickel Coatings.

The emergence of defects during the early production phases of ferrous-alloy additively manufactured (AM) parts poses a serious threat to their versatility and adversely impacts their overall mechanical performance in industries ranging from aerospace engineering to medicine. Lack of fusion and gas entrapment during the manufacturing stages leads to increased surface roughness and porosities in the finished part. In this study, the efficacy of employing electroless nickel-boron (Ni-B) deposition to fill and level simulated AM defects was evaluated. The approach to levelling was inspired by the electrochemical deposition techniques used to fill vias in the electronics industry that (to some extent) resemble the size and shape of AM-type defects. This work investigated the use of surfactants to attenuate surface roughness in electroless nickel coatings, thereby achieving the preferential inhibition of the coating thickness on the surface and promoting the filling of the simulated defects. A cationic surfactant molecule, CTAB (cetyltrimethyl ammonium bromide), and a nonpolar surfactant, PEG (polyethylene glycol), at different concentrations were tested using a Ni-B electrolyte for the levelling study. It was found that the use of electroless Ni-B to fill simulated defects on ferrous alloys was strongly influenced by the concentration and nature of the surfactant. The highest levelling percentages were obtained for the heavy-molecular-weight PEG-mediated coatings at 1.2 g/L. The results suggest that electroless Ni-B deposition could be a novel and facile approach to filling defects in ferrous-based AM parts.

An Early Machining Time Estimation for Make-to-Order Manufacturing Using Machine Learning Approach

The machining time estimation of an early production phase is a critical procedure in the make-to-order (MTO) industry for production scheduling and cost estimation processes. However, the existing computer-aided manufacturing (CAM) software used in computer numerical control (CNC) machining time estimation often falls short due to its limited consideration of toolpath control tolerance and geometry. In light of this, our study takes a novel approach by developing three machine learning-based models that incorporate extensive CAM data, including tolerance and geometry-related parameters, to estimate the machining time of MTO-based CNC manufacturing. These models, which include multiple linear regression, gradient boosting trees, and artificial neural networks (ANN), were trained using a case study from an MTO manufacturing company. The results of our study demonstrate that the CNC machining time is significantly influenced by tolerance or geometry-related variables, such as stepover and strategy type, in addition to other expected traditional parameters, including cut length and machining thickness. The validation process further confirmed the superiority of our ANN model, which produced estimations with the lowest Root Mean Squared Error (RMSE), achieving 196.35 s of RMSE on the testing data. This was a remarkable 72% lower than the RMSE produced by benchmark CAM software. Our proposed method thus represents a significant advancement in machining time estimation, with implications for the critical decisions made during the order negotiation phase of the MTO industry.

Investigation of time series-based genre popularity features for box office success prediction.

Predicting the profitability of movies at the early phase of production can be helpful to support the decision to invest in movies however, due to the limited information at this stage it is a challenging task to predict the movie's profitability. This study proposes genre popularity features using time series prediction. We argue that a movie can produce better box office returns if its genre's popularity is high at the time of release. The novel genre popularity features are proposed in terms of budget, revenue, frequency, success, and return on investment (ROI). The proposed features couple the predicted genre popularity with release time, in order to train the machine learning classifiers. The experimentation shows that the Gradient Boosting classifier gained a significant improvement using proposed features and achieved an accuracy of more than 92.4%, i.e., 35.7% better than an existing state of the art study considering a multi-class problem.

Utilisation of locust bean (Parkia biglobosa) pulp as a natural egg quality enhancer in laying hens

Abstract This study was carried out to improve commercial egg production using parkia pulp which is usually washed off during the processing of parkia seed into spice. A total of 54 Hyline brown Agrited brand pullets were randomly allotted to 3 treatments, 6 birds per replicate. Parkia pulp was included in the birds’ drink (0%, 1%, and 2% parkia pulp) from 08:00 h to 10:00 h followed by clean cool water daily from day 147 to day 245 (early egg production phase). At day 420 to 448 (late egg production phase) conventional multivitamins, 1% and 2% parkia pulp were included in drinking water for 3 days in a week 08:00 h to 17:00 h. Data on the growth of birds, egg production, and egg internal and external quality were measured and analysed using ANOVA at p &lt; 0.05. The weight of birds in the early egg production phase was directly proportional to the quantity of parkia pulp included in the parkia pulp drink. The number of eggs produced per bird (64.85) was significantly higher from the birds on 1% parkia pulp drink, whereas from the egg quality indicators, egg weight (65.03 g), length (56.15 mm), shell weight (8.06 g), and albumen weight (41.75 g) were all significantly higher at 2% inclusion level of parkia pulp drink in the early stage of egg production. In the late phase there was no significant difference among the treatments in the internal and external egg qualities but the weight of birds on parkia drink was high at p ≤ 0.05. The results of our study show that parkia pulp inclusion in commercial laying hen drink enhances the quality and quantity of egg production.

Boswellic acids, as novel inhibitor targeting peptidoglycan biosynthetic enzyme UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) in Escherichia coli

UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) is an essential cytosolic enzyme in the biosynthesis of peptidoglycan. It becomes a potential bacterial target for screening promising antibacterial compounds as it is associated with the early phases of peptidoglycan production. MurA enzyme is conserved and necessary for bacterial viability with no mammalian homolog, which is a well-proven therapeutic research target. The present study reports the natural compounds from Boswellia serrata targeting the MurA enzyme. The identified inhibitors against MurA Escherichia coli (E. coli): β-boswellic acid (IC50 33.65µM), Acetyl-β-boswellic acid (IC50 30.17µM), and Acetyl-11-keto-β-boswellic acid (IC50 37.67µM). Inhibitors showed a fourfold decrease in IC50 values on pre-incubation with substrate-UDP-N-acetyl-glucosamine (UDP-GlcNAc). Mode-of-inhibition studies revealed their uncompetitive nature with both the substrates. Although these boswellic acids have been explored for their pharmacological potential, this is the first study reporting these compounds' E. coli MurA inhibiting potential.

E&amp;P Notes (May 2022)

E&amp;P Notes (May 2022)

Interspecific Usurpation in the Downy Yellowjacket, Vespula flavopilosa (Hymenoptera: Vespidae)

We report 12 new observations of parasitically-founded Vespula flavopilosa colonies. Of these, 4 nests were identified directly by having been found in the pre-emergence stage, whereby only the resident queen was seen foraging before the presence of the first workers. Seven nests were found in the early phases of worker production, wherein the queen and first workers were foraging simultaneously, or nests were observed containing workers of both the host V. maculifrons and parasite V. flavopilosa freely foraging together. A twelfth nest, collected later in the season, appeared to have been the result of a usurpation of a V. germanica nest, based on gray paper found in the central cores of the first three combs of the nest. This represents the first report of V. flavopilosa utilizing the introduced V. germanica as a host species. These observations cover a wide part of the species' range, and imply that V. flavopilosa is a frequent temporary social parasite. Furthermore, this behavior appears to be obligatory since an incipient nest founded unequivocally by a V. flavopilosa queen has not been recorded.

Inspecting non-linear behavior of aggregated and disaggregated renewable and non-renewable energy consumption on GDP per capita in Pakistan

This research assessed that how various sources of energy such as renewable, fossil fuel, electricity generation using oil, and hydroelectric sources can influence the level of output in Pakistan. For this purpose, the ARDL bounds test using annual time series data from 1980 to 2019 is used to determine the cointegration relationship between output per person and various sources of energy. The empirical results disclose that the linear terms of fossil fuel energy consumption and electricity production using oil sources significantly enhance economic growth while the squared terms of both significantly deteriorate economic growth both in the long and short-run in Pakistan. This confirms that fossil fuel has an inverted U-shaped influence on output per person in the long run as well as in the short-run period in Pakistan. Besides this, economic growth significantly falls due to a one percent increase in linear terms of renewable energy consumption and electricity production using hydroelectric sources in long run but economic growth significantly increases due to a one percent increase in the squared term of both terms. This provides evidence of the U-shaped consequence of renewable energy consumption on output level only for the long-run period. In short, the study concludes that the aggregate and disaggregate energy sources reveal similar results on the output. The study suggests that giving a boost to economic growth using fossil fuel is may be fruitful in the early phase of production but in the later phase of production it is not fruitful whereas the use of clean energy although is not beneficial in the early phase of production in expanding production activities in Pakistan but in the later phase of production it is fruitful for production but also for the environment. Therefore, the present study proposes that government may take serious efforts to shift its emphasis from nonrenewable to renewable energy sources to fulfill energy requirements for achieving sustainable economic growth in Pakistan.

An Artificial-Intelligence-Driven Predictive Model for Surface Defect Detections in Medical MEMS.

With the advancement of miniaturization in electronics and the ubiquity of micro-electro-mechanical systems (MEMS) in different applications including computing, sensing and medical apparatus, the importance of increasing production yields and ensuring the quality standard of products has become an important focus in manufacturing. Hence, the need for high-accuracy and automatic defect detection in the early phases of MEMS production has been recognized. This not only eliminates human interaction in the defect detection process, but also saves raw material and labor required. This research developed an automated defects recognition (ADR) system using a unique plenoptic camera capable of detecting surface defects of MEMS wafers using a machine-learning approach. The developed algorithm could be applied at any stage of the production process detecting defects at both entire MEMS wafer and single component scale. The developed system showed an F1 score of 0.81 U on average for true positive defect detection, with a processing time of 18 s for each image based on 6 validation sample images including 371 labels.

Transcriptome Response of Liver and Muscle in Heat-Stressed Laying Hens.

Exposure to high ambient temperature has detrimental effects on poultry welfare and production. Although changes in gene expression due to heat exposure have been well described for broiler chickens, knowledge of the effects of heat on laying hens is still relatively limited. In this study, we profiled the transcriptome for pectoralis major muscle (n = 24) and liver (n = 24), during a 4-week cyclic heating experiment performed on layers in the early phase of egg production. Both heat-control and time-based contrasts were analyzed to determine differentially expressed genes (DEGs). Heat exposure induced different changes in gene expression for the two tissues, and we also observed changes in gene expression over time in the control animals suggesting that metabolic changes occurred during the transition from onset of lay to peak egg production. A total of 73 DEGs in liver were shared between the 3 h heat-control contrast, and the 4-week versus 3 h time contrast in the control group, suggesting a core set of genes that is responsible for maintenance of metabolic homeostasis regardless of the physiologic stressor (heat or commencing egg production). The identified DEGs improve our understanding of the layer’s response to stressors and may serve as targets for genetic selection in the future to improve resilience.

Cigarette Smoke Exposure Inhibits Early Phase of Antibody Production through Inhibition of Immune Functions in Alveolar Macrophage

Background::Cigarette smoke (CS) is inhaled into the lung. Alveolar macrophage (AM) is known to play an important role in the lung immune system. However, the relationship between AM functions and antibody production by CS is not fully investigated.Objective::Therefore, we investigated the effects of AM from CS exposed mice on antibody production. Mice were exposed to 20 cigarettes/day for 10 days. AM were obtained by broncho-alveolar lavage. Antibody production was analyzed by plaque-forming cell assay using seep red blood cell (SRBC) as antigen.Methods::B cell proliferation was analyzed by 3H-thymidine incorporation. Phagocytic activity using fluorescein isothiocyanate-labeled SRBC and expressions of surface antigens on AM were analyzed by flow cytometry. Cytokines and NF-κB mRNA expressions of AM were analyzed by RTPCR.Results and Discussion:Antibody production was decreased at the induction phase, but not at the expression phase by AM from smoked mice (SM) compared with non-smoked mice (NSM). B cell proliferation was decreased by cigarette extracts dose-dependently. Phagocytic activity of AM was decreased in SM compared with NSM. Expression of surface antigens on AM was decreased in SM compared with NSM. Cytokines or NF-κB mRNA expressions of AM were decreased in SM compared with NSM.Conclusion::These results suggest that the inhibition of antibody production by cigarette smoking is caused by the inhibition of phagocytosis and expressions of surface antigens associated with antigen presentation. Such inhibition of AM functions may increase the risk of bacterial and virus infections.

Study on the Erosion of Screen Pipe Caused by Sand-Laden Slurry

Screening is one of the main filtration and separation methods for unconsolidated sandstone reservoirs, and the problem of failure of sand control screen, encountered by some sand control wells in early production phase, gives rise to serious sand production in the shaft and influences normal production in the oilfield. In order to analyze the reason for screen failure in sand control wells and the detailed mechanism of the short service cycle of sand control screens, this paper proposes an experimental device, which can simulate sand screen erosion by the sand-laden slurry under underground working conditions and studies the influence of screen type, salinity, sand particle size, sandladen concentration, erosive angle, and other factors on the degree of erosion of screen filtering medium. Based upon experimental results, the current study establishes a model for predicting the service-life of sand control screens. The results showed that the jet velocity, sand-laden concentration, sand particle size, erosive angle, and other factors exhibited an obvious influence on the erosion of screen, while the salinity of formation water exerted an insignificant influence. Under the same conditions, different types of screens presented relatively significant differences in antierosion performance, whereas the anti-erosion performance of the stars screen was found to be superior to that of the metal mesh screen. The results provide some basis for selecting sand control methods, offering guidance about the production systems and predicting the service-life of screens.

Plantar flexor strength at different knee positions in older and young males and females.

This study examined the effects of age and knee position (fully extended, K0; 90° flexed, K90) on plantar flexor maximal voluntary contraction (MVC) torque and the rate of torque development (RTD) in both sexes. The following parameters were measured in 32 older (66-81yr, 17 males and 15 females) and 37 young (20-30yr, 18 males and 19 females) adults: evoked peak twitch torque, time to peak twitch torque, RTD of the twitch torque, MVC torque, RTD at early (0-50ms, RTD0-50) and later (100-200ms, RTD100-200) time intervals during explosive contractions, voluntary activation (VA%) during MVC, root mean square of the electromyogram (RMS-EMG) during MVC and explosive contractions, thickness of the triceps surae, and pennation angle of the medial gastrocnemius. The magnitudes of the differences were interpreted based on Cohen's d (d). Age-related difference in RTD0-50 was greater for females (d=1.36) than males (d=1.03) and vice versa for MVC torque and RTD100-200. For young adults, MVC torque, RTDs, and RMS-EMGs of the gastrocnemius but not the soleus were significantly higher in K0 than in K90. For older adults, no differences in voluntary RTDs were observed between K0 and K90, and RMS-EMGs of the gastrocnemius were higher in K90 than in K0, except for that of the lateral gastrocnemius in the early time intervals during explosive contraction. The age-related difference in the effect of knee position for RTD0-50 was higher in females than males, and vice versa for MVC torque and RTD100-200. The results suggested that the effects of age and knee joint angle on the plantar flexor performance were more prominent in the early phase of force production for females and were more apparent in the later phase and maximal force for males.

SOCIOECONOMIC ASPECTS OF CERAMIC PRODUCTION IN ROMAN THRACE

The province of Thrace was established in ca. AD 45-46 on the territory of the last Thracian Kingdom. In the course of more than two hundred years, between the second half of the First and the late Third century, ceramic production was developed in an unprecedented scale in this territory, in both rural and urban context. A number of rural settlements in Thrace, including agricultural estates ( villae ), agrarian and artisan’s villages ( vici ), have accommodated pottery and tile workshops since the second half of the First – the beginning of the Second century. From the late First – early Second century onwards potteries were established also in towns and cities. The data analysed and presented for the location and internal organisation of the ceramic workshops in Thrace indicates that the most widespread type of organised production was the individual workshop. Some of these ateliers were clustered near available resources and developed trade routes, and occasionally incorporated in single settlement units. However, the considerable size and complex layout of the workshops from the early phase of ceramic production under Roman rule could be viewed as a proof that the craft was initially developed by people with certain financial abilities and social status (local dynasts, immigrant civilians, enfranchised itinerant and indigenous army veterans). These individuals were among the first to perceive and advertise the Roman way of life through, on the one side, the new construction techniques and materials, and, on the other, the concomitant culture of eating and drinking, visible through the archaeological discoveries of pottery and other vessels used for these purposes.

Chemical and sensory changes during shelf-life of UHT hydrolyzed-lactose milk produced by “in batch” system employing different commercial lactase preparations

Manufacturing shelf-stable Ultra-high temperature hydrolyzed-lactose milk (UHLM) is a challenge for dairy producers, as the product undergoes chemical changes during storage due to both reducing sugars reactivity and proteolysis arising from the impurity of the lactase preparations. In the present study, the “in batch” production system, which includes the addition of the lactase before the thermal treatment, was demonstrated a valuable alternative to the more popular “in pack” system, where lactase is added directly into each milk package after thermal sterilization. The features of the technology were investigated by monitoring the changes in free amino acids, volatile organic compounds, color and sensory properties of UHLMs produced with three different lactase preparations (LPs), up to 120 days at 20 °C. Upon UHT processing, the proteolytic side activity of lactases was minimized, so minimum breakdown of milk protein was achieved. The release of free amino acids was dependent on the lactase purity only in the early production phases, whereas it did not change over time. The Strecker aldehydes benzaldehyde and 2-methylbutanal resulted as effective markers to correlate with the initial lactase purity during storage. Color and sensory slightly changed during storage but were poorly correlated with the different lactases, resembling to phenomena typical of milk aging. This latter result suggested that production costs might be lowered by opting for less-purified lactases when considering the “in batch” technology, supporting the application of this production system for the design of UHLM with high-quality standards and low risk of alterations during shelf-life.