Increasing global population implies a growing demand for animal products such as meat, milk and eggs. However, this leads to increased pressure on natural resources for the production of animal feed raw materials, which compete with human food resources. Therefore, there is a growing interest in finding alternative and sustainable protein sources for animal feed. In Italy the egg market, despite various adversities that have occurred in recent periods, has guaranteed national needs, succeeding in the goal of producing safe food for the end consumer. Over the past 40 years, egg consumption has tripled, and consequently so has its demand, a result of increased consumer awareness and knowledge about their nutritional value. Eggs, in fact, are perceived by consumers as a complete food, rich in high biological value protein, low in cost and with high nutritional value. Although there has been misinformation in the past regarding the association between egg consumption and increased cholesterol in humans, in addition to traditional table eggs, a new profitable segment has been added to the egg market in recent years, which has enabled the growth in demand for eggs and egg products. This segment refers to eggs enriched with nutrients, specifically omega-3 fatty acids, resulting in products with greater functional properties: so-called 'omega-3 enriched eggs' or 'designer eggs'; mainly affecting lipid characteristics, toward which there has long been great attention in correlation with cardiovascular disease. With this in mind, the present thesis to evaluated the effect of the dietary supplementation with whole hemp (Cannabis sativa L.) seeds on the quality and nutritional value of eggs. For this purpose, 1800 HyLine Brown laying hens aged 36 to 40 weeks were used. The animals were placed in an experimental aviary divided into 8 pens. Hemp seeds (10% inclusion level of the daily feed intake), from a mixture of the two cultivars Felina 32 and Futura 75 were distributed daily in circular feeders (two pens) or on the litter (two pens). All hens (four enriched pens and four control pens without hemp seed enrichment) were fed a commercial diet of soybean meal and corn ad libitum. A total of 480 eggs (60 per pen) were collected at two different times, after 14 and 28 days of enrichment with hemp seeds. On average of the two samplings, enrichment with whole hemp seeds did not bring about any changes on physical, rheological and nutritional quality of eggs (P > 0.05), except for the increase of L* index and yolk pH (P < 0.001) and of albumen pH (P < 0.05). On the contrary, such enrichment led to a change in the lipid composition of the yolk, with a reduction in total saturated (P < 0.001) and monounsaturated (P < 0.05) fatty acids, and an increase in total polyunsaturated fatty acids, especially those of the omega-3 (P < 0.001) and omega-6 (P < 0.05) series. Sensory analysis conducted on hard-boiled eggs showed that 46% of the tasters detected the difference between the two eggs coming from hens enriched or not enriched with hemp seeds, with no preference found between the two samples (P > 0.05). In conclusion, enrichment with whole hemp seeds for 10% of the daily feed intake of laying hens did not result in any negative effects on egg quality, bringing an increase in the n-3 fatty acids of the yolk after 4 weeks of experimentation without any influence on consumers’ preference.
L’aumento della popolazione globale implica una crescente richiesta di prodotti di origine animale come carne, latte e uova. Tuttavia, questo porta ad una maggiore pressione sulle risorse naturali per la produzione di materie prime dei mangimi per animali, che entrano in competizione con le risorse alimentari umane. Pertanto, c'è un interesse in crescita nella ricerca di fonti proteiche alternative e sostenibili per l'alimentazione animale. A livello italiano, la produzione di uova ha garantito il fabbisogno nazionale, riuscendo nell’obiettivo di produrre alimenti sicuri per il consumatore finale. Negli ultimi 40 anni il consumo di uova è triplicato, e di conseguenza la sua domanda, risultato di una maggiore consapevolezza e conoscenza da parte del consumatore riguardo al loro valore nutrizionale. Le uova sono percepite dal consumatore come un alimento completo, ricco di proteine ad alto valore biologico, a basso costo e con elevato valore nutrizionale. Nonostante in passato ci sia stata l’associazione fra consumo di uova e incremento del colesterolo nell’uomo, oltre alle tradizionali uova da tavola, negli ultimi anni si è aggiunto al mercato delle uova un nuovo segmento redditizio, che ha permesso la crescita della domanda di uova e prodotti derivati. Tale segmento si riferisce a uova arricchite con nutrienti, nello specifico acidi grassi omega-3, ottenendo prodotti con maggiori proprietà funzionali: le cosiddette ‘uova arricchite con omega-3’ o ‘uova di design’; incidendo principalmente sulle caratteristiche dei lipidi, verso cui da tempo c’è grande attenzione in correlazione alle malattie cardiovascolari. Premesso ciò, l’attività sperimentale del seguente elaborato ha avuto come scopo la valutazione dell’effetto dell’integrazione alimentare con semi di canapa interi (Cannabis sativa L.), su qualità e valore nutrizionale delle uova. A questo scopo sono state utilizzate 1800 galline ovaiole di razza HyLine Brown di età compresa tra le 36 e 40 settimane. Gli animali sono stati collocati in un aviario sperimentale suddiviso in 8 recinti. I semi di canapa (livello di inclusione del 10% rispetto al fabbisogno giornaliero), di una miscela delle due cultivar Felina 32 e Futura 75 sono stati distribuiti giornalmente in mangiatoie circolari (due recinti) e sparsi sulla lettiera (due recinti). Tutti gli animali (4 recinti con arricchimento e 4 recinti senza arricchimento con semi di canapa) sono stati alimentati con una dieta commerciale a base di farina di soia e mais ad libitum. Un totale di 480 uova (60 per recinto) è stato raccolto in due momenti differenti, dopo 14 e 28 giorni di integrazione con la canapa. In media, l’arricchimento con semi di canapa interi non ha modificato le caratteristiche qualitative fisiche, reologiche e nutrizionali delle uova (P > 0,05), con l’eccezione dell’aumento dell’indice L* e del pH del tuorlo (P < 0,001) e del pH dell’albume (P < 0,05). Al contrario, tale arricchimento ha modificato il profilo acidico del grasso del tuorlo, con una riduzione degli acidi grassi saturi (P < 0,001) e monoinsaturi (P < 0,05), ed un incremento degli acidi grassi polinsaturi, soprattutto quelli della serie omega-3 (P < 0,001) ed omega-6 (P < 0,05), rispetto alle uova di controllo che non avevano ricevuto integrazione con i semi di canapa. Dall’analisi sensoriale condotta su uova sode è risultato che il 46% degli assaggiatori ha rilevato la differenza tra le uova di gallina che avevano ricevuto integrazione e quelle che non avevano ricevuto l’integrazione, senza nessuna preferenza tra le uova dei due gruppi (P > 0,05). In conclusione, l’arricchimento con semi di canapa interi al 10% del consumo giornaliero non ha modificato la qualità delle uova e ha modificato la composizione degli acidi grassi del profilo lipidico del tuorlo dopo 4 settimane di integrazione senza alcuna influenza sulla preferenza dei consumatori.
Effetto dell'arricchimento alimentare con semi di canapa (Cannabis sativa L.) sulla qualità delle uova di galline ovaiole
LATROFA, ANTONELLA
2023/2024
Abstract
Increasing global population implies a growing demand for animal products such as meat, milk and eggs. However, this leads to increased pressure on natural resources for the production of animal feed raw materials, which compete with human food resources. Therefore, there is a growing interest in finding alternative and sustainable protein sources for animal feed. In Italy the egg market, despite various adversities that have occurred in recent periods, has guaranteed national needs, succeeding in the goal of producing safe food for the end consumer. Over the past 40 years, egg consumption has tripled, and consequently so has its demand, a result of increased consumer awareness and knowledge about their nutritional value. Eggs, in fact, are perceived by consumers as a complete food, rich in high biological value protein, low in cost and with high nutritional value. Although there has been misinformation in the past regarding the association between egg consumption and increased cholesterol in humans, in addition to traditional table eggs, a new profitable segment has been added to the egg market in recent years, which has enabled the growth in demand for eggs and egg products. This segment refers to eggs enriched with nutrients, specifically omega-3 fatty acids, resulting in products with greater functional properties: so-called 'omega-3 enriched eggs' or 'designer eggs'; mainly affecting lipid characteristics, toward which there has long been great attention in correlation with cardiovascular disease. With this in mind, the present thesis to evaluated the effect of the dietary supplementation with whole hemp (Cannabis sativa L.) seeds on the quality and nutritional value of eggs. For this purpose, 1800 HyLine Brown laying hens aged 36 to 40 weeks were used. The animals were placed in an experimental aviary divided into 8 pens. Hemp seeds (10% inclusion level of the daily feed intake), from a mixture of the two cultivars Felina 32 and Futura 75 were distributed daily in circular feeders (two pens) or on the litter (two pens). All hens (four enriched pens and four control pens without hemp seed enrichment) were fed a commercial diet of soybean meal and corn ad libitum. A total of 480 eggs (60 per pen) were collected at two different times, after 14 and 28 days of enrichment with hemp seeds. On average of the two samplings, enrichment with whole hemp seeds did not bring about any changes on physical, rheological and nutritional quality of eggs (P > 0.05), except for the increase of L* index and yolk pH (P < 0.001) and of albumen pH (P < 0.05). On the contrary, such enrichment led to a change in the lipid composition of the yolk, with a reduction in total saturated (P < 0.001) and monounsaturated (P < 0.05) fatty acids, and an increase in total polyunsaturated fatty acids, especially those of the omega-3 (P < 0.001) and omega-6 (P < 0.05) series. Sensory analysis conducted on hard-boiled eggs showed that 46% of the tasters detected the difference between the two eggs coming from hens enriched or not enriched with hemp seeds, with no preference found between the two samples (P > 0.05). In conclusion, enrichment with whole hemp seeds for 10% of the daily feed intake of laying hens did not result in any negative effects on egg quality, bringing an increase in the n-3 fatty acids of the yolk after 4 weeks of experimentation without any influence on consumers’ preference.File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.12608/61863