Exploration of Foods and Foodomics

Table 3. Volatile and metabolic components of bio-yogurt supplemented with threonine (0, 1, 5, and 10 mg/100 mL of milk) during a 21-day storage period.

Physicochemical tests	Threonine (mg/100 mL of milk)	Storage periods (days)
Physicochemical tests	Threonine (mg/100 mL of milk)	1	7	14	21
Lactic acid (mg/kg)	0	43.21^a ± 1.35	49.88^c ± 1.22	56.20^a ± 1.10	64.44^c ± 2.09
	1	44.03^a ± 2.01	50.11^b ± 2.02	56.86^a ± 2.00	65.00^b ± 2.41
	5	44.88^a ± 1.91	50.55^b ± 1.96	57.15^a ± 1.88	65.55^b ± 2.17
	10	45.73^b ± 2.11	51.10^a ± 2.05	57.28^a ± 2.02	67.02^a ± 2.44
Acetic acid (mg/kg)	0	20.23^a ± 0.88	25.00^b ± 1.00	28.86^c ± 0.05	33.01^ab ± 0.08
	1	20.90^a ± 0.65	25.92^a ± 0.97	29.03^ab ± 0.05	33.46^a ± 0.06
	5	21.55^a ± 0.77	26.49^a ± 0.57	29.67^a ± 0.05	33.93^a ± 0.09
	10	21.94^a ± 0.91	26.99^a ± 0.93	30.01^a ± 0.05	34.27^a ± 0.08
Acetoin (μg/kg)	0	22.50^d ± 1.05	22.51^d ± 0.96	21.82^c ± 0.98	20.08^c ± 0.91
	1	25.11^c ± 1.11	25.19^c ± 1.02	23.88^ab ± 0.65	22.09^b ± 0.96
	5	26.23^b ± 2.03	26.27^b ± 1.06	25.00^b ± 0.99	24.61^a ± 0.99
	10	29.02 ^a ± 1.19	29.14^a ± 0.99	27.50^a ± 0.92	26.13^a ± 0.97
Diacetyl (μg/kg)	0	2.55^c ± 0.02	2.53^c ± 0.01	2.12^b ± 0.03	2.03^c ± 0.10
	1	3.09^ab ± 0.05	3.11^ab ± 0.13	3.00^a ± 0.09	2.86^ab ± 0.08
	5	3.48^a ± 0.01	3.50^a ± 0.06	3.22^a ± 0.08	3.02^a ± 0.09
	10	3.97^a ± 0.04	3.96^a ± 0.05	3.80^a ± 0.10	3.55^a ± 0.05
Ethanol (mg/kg)	0	27.12^a ± 0.11	25.11^a ± 0.33	22.76^a ± 0.15	19.00^a ± 0.53
	1	27.50^a ± 0.15	25.71^a ± 0.15	22.09^a ± 0.25	19.16^a ± 0.06
	5	27.85^a ± 0.33	24.58^a ± 0.08	20.44^b ± 0.05	17.13^b ± 0.29
	10	28.44^a ± 0.52	24.11^a ± 0.12	20.31^b ± 0.11	16.99^b ± 0.17
Acetaldehyde (μg/kg)	0	38.23^d ± 0.22	36.64^d ± 0.71	35.82^d± 0.35	32.21^c ± 0.29
	1	42.12^c ± 0.56	42.19^c ± 0.78	40.28^c ± 0.63	40.00^ab ± 0.37
	5	46.13^b ± 0.49	46.63^b ± 0.41	45.08^b ± 0.81	44.99^a ± 0.58
	10	49.40^a ± 0.59	49.62^a ± 0.33	47.06^a ± 0.58	46.95^a ± 0.58

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a, b, c: different letters in columns indicate significant differences at p < 0.05.

Declarations

Author contributions

STGAS: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Software, Visualization, Project administration, Writing—original draft. AKN: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Software, Visualization, Supervision, Validation, Writing—original draft, Writing—review & editing. Both authors read and approved the submitted version.

Conflicts of interest

The authors declare that they have no conflicts of interest.

Ethical approval

The study involved a standardized sensory evaluation of food products, and informed consent was obtained from all participants before testing. The protocol posed no health risks, and the Food Science department/University of Basrah exempted the study from formal ethical approval. Sensory assessment was conducted in accordance with the ethical principles of the Declaration of Helsinki.

Consent to participate

Informed consent was obtained from all participants to participate in the sensory assessment in the study.

Consent to publication

Not applicable.

Availability of data and materials

The raw data supporting the conclusions of this manuscript will be made available by the authors, without undue reservation, to any qualified researcher.

Funding

The authors received no funding to complete this study.

Copyright

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Open Exploration maintains a neutral stance on jurisdictional claims in published institutional affiliations and maps. All opinions expressed in this article are the personal views of the author(s) and do not represent the stance of the editorial team or the publisher.

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