Raw Organic Goat Milk Composition, Microbiological Parameters, and Quality Traits of Milk Samples from Three Farms in Germany over Three Years (2023-2025)

GENERAL INFORMATION

Project title
Optimization of cheese quality in organic artisanal goat milk processing considering raw milk variations
Website associated with the project: https://www.ziegenkaesequalitaet.de/

Project description
The majority of organic goat milk farms in Germany processes the milk in farmhouse dairies, aiming to produce an authentic cheese quality with a high consumption value. Small-scale dairies can only realize their economic potential of on-farm processing if they achieve consistently high cheese quality. However, experience shows that quality variation in goat milk occurs on farms during the lactation period, which may result in cheese defects, i.e., undesirable sensory deviations from their quality standard, if the on-farm-processing is not adapted to the milk quality. The aim of the project is therefore to examine the milk quality and to identify correlations to cheese-making characteristics and sensory quality of organic goat cheese. In addition, cheesemaking trials are conducted to develop and test technological measures (process parameters) to adapt to fluctuations in the milk quality. The collaborative partner VHM is responsible for the knowledge transfer measures.

Data set description
The data set contains 176 independent samples of raw organic goat's milk parameters obtained from three farms over three years. Goat breeds include German Improved Fawn and White, Thuringian Forest goats, or crossbred goats. Analyzed parameters are total bacterial count (TBC) and somatic cell count (SCC), content of fat, total protein, casein and calcium, pH, and titratable acidity. Raw milk samples were collected from bulk milk tanks in a regular sequence of 2 weeks within the lactation period (approx. from March to November). 356 independent observations are missing and a total of 10 observations were excluded from the data set. In some cases, logistical challenges and plannings necessitated a shift in the sampling interval. 

METHODOLOGICAL INFORMATION

Sample collection
Raw milk samples were collected from bulk milk tanks at approx. 4 °C while milk was stirred. Approx. 125 mL of milk was sampled twice and analyses were performed in duplicate by a dairy laboratory accredited according to ISO 17025:2018. Milk samples were stored in insulated boxes, and equipped with special cool packs to ensure refrigerated transport below 8 °C for up to 24-48 hours. Samples were dispatched to the dairy laboratory by express delivery. Metrics about the date of collection, the date of analysis, and the shipping conditions are included in the data set.

Analytical methods
Total bacterial count (TBC) and somatic cell count (SCC) were determined by flow cytometry using BacSomatic (Foss, Hillerød, Denmark). For interpretation of TBC and SCC, ASU L 01.01-7 / May 2022 and ASU L01.01-1/September 1998 were applied, respectively. Fat content was measured according to Gerber method, VDLUFA C 15.3.2 / 1985-01 and protein content was measured by Kjeldahl, VDLUFA C 30.2 / 1985-01. Casein content was calculated by applying VDLUFA C 30.4. Calcium was determined according to VDLUFA C10.6.8. Soxhlet-Henkel acidity (°SH) was obtained by titration according to VDLUFA Method 4.1.1. All methods are part of VDLUFA-Methodenbuch (2010), Vol. VI: Chemische, physikalische und mikrobiologische Untersuchungsverfahren für Milch, Milchprodukte und Molkereihilfsstoffe, VDLUFA-Verlag: Darmstadt, 7. edition. Information on the unit and a description of the parameters is provided in the variable list below. The accreditation of the laboratory refers to all the mentioned methods except for determination of pH and °SH. 

Data review
Test results from the laboratory were used as primary data source. Upon receipt, the data was reviewed for plausibility. The results of each sample were subsequently verified by a second reviewer to ensure accuracy. Some results were excluded from the dataset; these exclusions are documented and further explained in a separate file and labelled 'NP' in case of “not plausible” in the file, while missing data is labelled 'NA'. As the present work constitutes a data publication, no further analytical procedures were applied at this stage.

Note on the interpretation of microbiological raw milk data
The dataset contains occasional observations with very high bacterial counts, which should be regarded as exceptional events. These individual values are not representative of the overall hygienic status of the farms and do not allow for general conclusions regarding husbandry conditions. The data reflect farm-level snapshots of raw milk at the time of sampling and were not collected within the framework of official monitoring programs or for the assessment of regulatory compliance. Outlying values were retained in the dataset; in the affected farms, farm-specific corrective measures were subsequently implemented, which is reflected in reduced bacterial counts in follow-up measurements.

RESTRICTION OF THE DATASET
The dataset will remain restricted until the related scientific paper has been published.